id
stringlengths
36
36
question
stringlengths
6
1.34k
answer
stringlengths
1
376
subject
stringclasses
1 value
image
imagewidth (px)
35
4k
cc7f65d5-bdd5-43ff-942b-c4e25a2804dd
A cube loses one vertex after a 'corner' is removed. This geometric shape is ___ (fill in the number).
3
math
6fd886c5-8a54-48bd-a6c0-b267e05e5062
In a certain public welfare activity, Xiao Ming conducted a statistical analysis of the donation situation of his classmates and drew an incomplete statistical chart as shown in the figure. Among them, the number of people who donated 100 yuan accounts for 25% of the total number of people in the class. What is the median of the donations this time?
20
math
d14ce504-7fa7-4ba7-829a-f7a4a97b3319
As shown in the figure, a car departs from station $$A$$, passes through station $$B$$ to station $$C$$, and then returns. On the way out, it stops at station $$B$$, but does not stop on the return trip. The speed of the car on the way out is $$40$$ kilometers per hour. What is the average speed of the car for the round trip in kilometers per hour?
45
math
82055694-be2b-4de9-8895-d72edf48de61
Execute the program flowchart shown in the figure. If the input value of $$n$$ is $$3$$, then the output value of $$s$$ is ______.
$$4$$
math
d2570007-6964-4b20-bd93-ddd8dcf9c8da
As shown in the figure, $$BC$$ is the diameter of $$ \odot O$$, and $$BC=6$$. The extension of $$CB$$ intersects the tangent line at point $$D$$ on $$ \odot O$$ at point $$A$$. If $$AD=4$$, then $$AB=$$ ___.
$$2$$
math
545fd10a-3b77-4fbe-8c62-fdef037fed77
As shown in the figure, in ΔABC, the angle bisectors of ∠B and ∠C intersect at point O. A line DE parallel to BC is drawn through point O, intersecting sides AB and AC at points D and E, respectively. If AB = 5 and AC = 4, then the perimeter of ΔADE is ______.
9
math
8e64c030-29b0-4ded-b904-707791935593
As shown in the figure, given lines $$l_{1}$$, $$l_{2}$$, $$l_{3}$$, and $$l_{1} \parallel l_{2} \parallel l_{3}$$, line $$AC$$ intersects $$l_{1}$$, $$l_{2}$$, $$l_{3}$$ at points $$A$$, $$B$$, $$C$$ respectively, and line $$FD$$ intersects $$l_{1}$$, $$l_{2}$$, $$l_{3}$$ at points $$F$$, $$E$$, $$D$$ respectively. Given $$AB:BC=3:2$$ and $$DF=20$$, then $$DE=$$ ___.
$$8$$
math
31c0fc56-97b4-4596-a408-2f3a0192efae
Plant 5 different types of crops in the 5 experimental fields shown in the figure (all 5 types of crops must be selected), with each field planting only 1 type of crop. How many different planting methods are there?
120
math
dd561fd1-acad-41ea-8228-5d22774399d7
As shown in the figure, $$AB\parallel CD$$, $$PB$$ bisects $$\angle ABC$$, $$PC$$ bisects $$\angle DCB$$. Then $$\angle P=$$ ___ degrees.
$$90$$
math
3e6760d9-fc51-4906-97b1-95fa95bf4a78
Given the following program: When $$x=3$$, $$y=4$$, $$z=5$$, the output result is ___.
$$48$$
math
f33246e3-819a-47b7-8159-6b6281d1e425
As shown in the figure, the line $$y = - \dfrac{4}{3}x + 4$$ intersects the $$x$$-axis and $$y$$-axis at points $$A$$ and $$B$$, respectively. After rotating $$\triangle AOB$$ 90° clockwise around point $$A$$, we get $$\triangle A O'B'$$. What are the coordinates of point $$B'$$?
$$(7,3)$$
math
b6df39cf-e850-4b01-8e19-b8fb18b0b349
The figure shows the unfolded net of a cubic box, with different numbers and letters on its surfaces. When folded along the dotted lines to form a cube, the sum of the numbers on opposite faces is equal. Then, $$x+y=$$ ______ .
11
math
9f32c32b-ae44-4ea2-b1b9-55df20703eab
As shown in the figure, the perimeter of $$\square ABCD$$ is $$16cm$$. $$AC$$ and $$BD$$ intersect at point $$O$$, and $$OE \bot AC$$ intersects $$AD$$ at $$E$$. Then the perimeter of $$\triangle DCE$$ is ___.
$$8cm$$
math
be91e477-7892-497e-a48f-40fa2223ee9c
The age distribution of 200 employees in a certain unit is shown in the figure. Now, 40 employees are to be selected as a sample using systematic sampling. All employees are randomly numbered from 1 to 200 and divided into 40 groups in numerical order (1 to 5, 6 to 10, ... 196 to 200). If the number drawn from the 5th group is 22, then the number that should be drawn from the 8th group is ___. If stratified sampling is used, the number of people to be drawn from the age group under 40 should be ___.
37 20
math
6b5ac825-b818-4c9a-a42a-647e5d8e4a0d
As shown in the figure, there are different paths connecting locations $$A$$, $$B$$, $$C$$, and $$D$$, and each segment can only be traversed once. The number of different ways to travel from location $$A$$ to location $$C$$ is ___.
$$7$$
math
8a8516ea-3ae0-450d-8c10-d86248be7ab6
In the rectangle $$ABCD$$, $$AB=3$$, $$BC=4$$. If the rectangle is folded along the diagonal $$BD$$, then the area of the shaded part in the figure is ___.
$$\dfrac{75}{16}$$
math
3d28d623-3631-4f6c-8797-6d4467eb213f
In early winter 2014, a small convenience store wanted to understand the relationship between the sales volume of hot tea $$y$$ (cups) and the temperature $$x (^{\circ}C)$$, and randomly recorded the number of cups of hot tea sold and the temperature on 4 days, creating the following table: From the data in the table, the linear regression equation $$\hat{y}=\hat{b}x+\hat{a}$$ was calculated, with $$\hat{b}\approx-2$$. Predict the sales volume of hot tea when the temperature is $$-5^{\circ}C$$. (Given the regression coefficient $$\hat b=\dfrac{\sum\limits_{i=1}^{n}{x_iy_i}-n\overline{x}\overline{y}}{\sum\limits_{i=1}^{n}x_i^{2}-n\overline{x}^{2}}$$, $$\hat{a}=\overline{y}-\hat b\overline{x}$$)
$$70$$
math
fd9a6da9-d5cc-43d3-bcca-fda9de56675e
The table below shows the frequency distribution of a sample data with a capacity of $$10$$. If the midpoint of each group is used to approximately calculate the mean of this set of data $$\overline{x}$$, then the value of $$\overline{x}$$ is ___.
$$\number{19.7}$$
math
dfe70af0-0f8e-4109-9ccf-e0d280e9940b
A middle school has launched a 'One Hour of Sunshine Sports' activity. Based on the school's actual situation, as shown in the figure, it has decided to offer four sports activities: 'A: Kick Shuttlecock, B: Basketball, C: Jump Rope, D: Table Tennis' (each student must choose one). To understand which activity the students like best, a random sample of students was surveyed, and the survey results were plotted in the statistical chart shown in the figure. Among the students who participated in the survey, the number of students who like the Jump Rope activity is ___.
40
math
de6e074c-bd47-4a96-a686-3ded2a6ed91e
As shown in the figure, the line $$l_{1}$$: $$y=k_{1}x+4$$ intersects with the line $$l_{2}$$: $$y=k_{2}x-5$$ at point $$A$$. They intersect the $$y$$-axis at points $$B$$ and $$C$$ respectively. Points $$E$$ and $$F$$ are the midpoints of segments $$AB$$ and $$AC$$ respectively. The length of segment $$EF$$ is ___
$$\dfrac{9}{2}$$
math
229fab7e-5765-45d2-a219-f388d065dca1
As shown in the figure, in rhombus $$ABCD$$, $$\angle B=60^{\circ}$$, and $$AB=4$$. What is the perimeter of the square $$ACEF$$ with side $$AC$$?
$$16$$
math
bcd463d7-1a5e-4582-81fb-272d0399236f
In the Tang Dynasty of China, the poet Wang Wei wrote in his poem: 'The bright moon shines among the pines, the clear spring flows over the stones.' Here, the bright moon and the clear spring are natural scenes, which remain unchanged. The adjective 'bright' corresponds to 'clear,' the noun 'moon' corresponds to 'spring,' the parts of speech remain unchanged, and the same applies to the other nouns. The unchanging properties in changes are widely present in both literature and mathematics. For example, we can use a geometric function board software to draw the parabola $$C$$: $$x^{2}=y$$ (as shown in the figure). Draw a line $$l$$ through the focus $$F$$ intersecting $$C$$ at points $$A$$ and $$B$$. Draw tangents to $$C$$ at points $$A$$ and $$B$$, and let these tangents intersect at point $$P$$. Draw a vertical line from point $$P$$ to the $$x$$-axis, intersecting $$C$$ at point $$N$$. Moving point $$B$$ along $$C$$, it is found that $$\dfrac{|NP|}{|NF|}$$ is a constant value. What is this constant value?
$$1$$
math
e1e18ec4-c087-48a3-8f25-4514aecbb73d
Uncle Li used a 60-meter-long fence to enclose a right trapezoid small garden against a wall (as shown in the figure). The area of this garden is ______ square meters.
400
math
2951450d-ee4f-4727-9d62-017893d1e013
As shown in Figure 1, it is a right-angled triangular paper piece, $$ \angle A=30^{ \circ }$$, $$BC=\quantity{4}{cm}$$, it is folded so that point $$C$$ lands on point $$C'$$ on the hypotenuse, with the fold line being $$BD$$, as shown in Figure 2. Then, Figure 2 is folded along $$DE$$, so that point $$A$$ lands on point $$A'$$ on the extension of $$DC'$$, as shown in Figure 3. The length of the fold line $$DE$$ is ___.
$$\dfrac{8}{3} \ \unit{cm}$$
math
c3819de4-274c-4be9-a6d3-7d1225838d77
Given the development of a cone as shown in the figure, where the central angle of the sector is $$120^{\circ}$$, and the radius of the base circle is $$1$$, what is the volume of the cone?
$$\dfrac{2\sqrt{2} \pi }{3}$$
math
cdfce964-0ad0-40ea-ae87-184637d9ff3e
In a marathon race, the stem-and-leaf plot of the results (in minutes) of 35 athletes is shown in the figure. If the athletes are ranked from best to worst as numbers 1 to 35, and a systematic sampling method is used to select 7 people, then the number of athletes whose results fall within the interval [139, 151] is ___.
4
math
30ee48f8-f947-4d9b-a5cb-d2c709be9451
As shown in the figure, fold one side of the rectangle $$ABCD$$, $$AD$$, so that point $$D$$ lands on point $$F$$ on side $$BC$$. It is known that the crease $$AE=5\sqrt{5}\ \unit{cm}$$, and $$\tan \angle EFC=\dfrac{3}{4}$$, then the perimeter of rectangle $$ABCD$$ is ___.
$$\quantity{36}{cm}$$
math
c5ffeeeb-133d-4d5c-a30e-38114cb7fe78
As shown in the figure, it is known that the graphs of the functions $$y=ax+2$$ and $$y=bx-3$$ intersect at point $$A\left(2,-1\right)$$. Based on the graph, the solution set for the inequality $$ax>bx-5$$ is ___.
$$x < 2$$
math
3c77a3d4-66c7-4228-93e4-6a4f71835753
As shown in the figure, △ABC is inscribed in ⊙O, ∠BAC = 120°, AB = AC = 4, and BD is the diameter of ⊙O. Then BD = ______.
8
math
ba6dcd36-93b1-4771-bf92-2f7a793630de
As shown in the figure, $$\triangle ABD$$ and $$\triangle ACE$$ are both equilateral triangles. The basis for determining that $$\triangle ADC \cong \triangle ABE$$ is ___.
$$SAS$$
math
867fd117-056f-41ca-803f-7927a1f2e237
As shown in the figure, in the 'Pascal's Triangle', the numbers above the diagonal line $$AB$$, indicated by the arrows, form a zigzag sequence: $$1$$, $$2$$, $$3$$, $$3$$, $$6$$, $$4$$, $$10$$, $$\cdots$$, let the sum of the first $$n$$ terms of this sequence be $$S_{n}$$, then $$S_{16}=$$ ___.
$$164$$
math
10d523e6-12ee-4fc5-8145-69b8e8fe56c9
Execute the program flowchart shown. If the input value of $$x$$ is $$1$$, then the output value of $$n$$ is ___.
$$3$$
math
31eb6997-de90-4869-8b28-90b5304c45be
As shown in the figure, the diagonals AC and BD of quadrilateral ABCD intersect at point O, and BD bisects AC. If BD = 8, AC = 6, and ∠BOC = 120°, then the area of quadrilateral ABCD is ___. (Leave the answer in radical form)
12√3
math
9b71b5bd-53c9-4787-bdab-2e506cf5c8a9
As shown in the figure, in rhombus $$ABCD$$, $$DE \bot AB$$ at $$E$$, $$DE=\quantity{6}{cm}$$, and $$\sin A=\dfrac{3}{5}$$, then the area of rhombus $$ABCD$$ is ___ $$\unit{cm^{2}}$$.
$$60$$
math
23d9570e-9c14-4675-8cab-cc88e8730f91
As shown in the figure, point O is the center of the regular pentagon ABCDE. Then the measure of ∠BAO is ___.
54°
math
e910ad3b-0064-4792-bf86-c9780353938e
In the figure, in circle $$\odot O$$, chord $$AD \parallel BC$$, $$DA=DC$$, and $$\angle AOC=160^{\circ}$$, then $$\angle BCO$$ is equal to ___ degrees.
$$30$$
math
c57a1e4a-7b37-42da-b6b4-55f2d1e791b4
If the probability distribution table of the random variable $$\eta$$ is as follows: then when $$P( \eta < x)=0.8$$, the range of the real number $$x$$ is ___.
$$\left ( 1,2\right \rbrack $$
math
fe1267b5-0830-45f1-8931-f7ec5105cd20
In the right-angled triangle ABC, ∠C = 90°, ∠A = 30°, and AB = 8 cm. Therefore, BC = ______ cm.
4
math
dfc6f1f9-8862-4fc5-9486-fcaa87d63806
Translating the small rhombus $$\lozenge$$ can create a beautiful 'Chinese Knot' pattern. Among the following four patterns, they are similar 'Chinese Knot' patterns formed by translating $$\lozenge$$. According to the pattern in the figures, the number of small rhombuses in the 20th pattern is ______.
$$800$$
math
8a3d7f64-1c08-4fde-b905-324c5caf290c
In the parallelogram $$ABCD$$, point $$E$$ is on side $$BC$$, and $$DE$$ intersects diagonal $$AC$$ at $$F$$. If $$CE=2BE$$, and the area of $$\triangle ABC$$ is $$15$$, then the area of $$\triangle FEC$$ is ______.
4
math
8b932a5f-7a05-4848-befc-22d994a96f69
As shown in the figure, the lines $$l_{1}$$, $$l_{2}$$, and $$l_{3}$$ represent three intersecting highways. A cargo transfer station is to be built such that it is equidistant from the three highways. How many possible locations are there?
$$4$$
math
75904c30-7651-4576-b05d-3440a26b174b
As shown in the figure, all triangles are right-angled triangles, and all quadrilaterals are squares. Given that $$S_1=9$$, $$S_2=16$$, and $$S_3=144$$, then $$S_4=$$______.
169
math
36448863-4eb4-4a05-bd95-b31c5aa03503
As shown in the figure, the outer contour of a park is quadrilateral $$ABCD$$, which is divided into four parts by the diagonals $$AC$$ and $$BD$$. The area of $$\triangle BOC$$ is $$2$$ square kilometers, the area of $$\triangle AOB$$ is $$1$$ square kilometer, and the area of $$\triangle COD$$ is $$3$$ square kilometers. The land area of the park is $$6.92$$ square kilometers. Therefore, the area of the artificial lake is ______ square kilometers.
0.58
math
c04c703c-ddda-407f-8e24-1643ada24adf
As shown in the figure, the three views of a geometric solid are two rectangles and one sector. The surface area of this geometric solid is ___.
$$12+15\pi $$
math
16c85c36-218f-403f-bc5a-63de08eb8623
As shown in the figure, it is given that $$\angle 1 = \angle 2$$, if one more condition is added to make the conclusion "$$AB \cdot DE = AD \cdot BC$$" true, then this condition can be ___.
$$\angle B = \angle D$$
math
8370d586-7cc8-443a-8df1-36006173001d
As shown in the figure, given that $$ABCD$$ is a square, $$P$$ is a point outside the plane of $$ABCD$$, and the projection of $$P$$ onto the plane $$ABCD$$ is exactly the center $$O$$ of the square. $$Q$$ is the midpoint of $$CD$$. If $$\overrightarrow{PA}=x\overrightarrow{PO}+y\overrightarrow{PQ}+\overrightarrow{PD}$$, then $$x+y=$$ ___.
$$0$$
math
0cc4b7e5-fcf0-4205-b77d-fbd7c86e338b
As shown in the figure, points $$A$$ and $$C$$ are on the graph of the inverse proportion function $$y=\dfrac{a}{x}$$ ($$a>0$$), and points $$B$$ and $$D$$ are on the graph of the inverse proportion function $$y=\dfrac{b}{x}$$ ($$b<0$$). $$AB\parallel CD\parallel x$$-axis, and $$AB$$ and $$CD$$ are on opposite sides of the $$x$$-axis. Given that $$AB=3$$, $$CD=2$$, and the distance between $$AB$$ and $$CD$$ is $$5$$, the value of $$a-b$$ is ___.
$$6$$
math
a736fa8e-edcf-491a-8ab3-237e8da13cbe
The students of a school come from three regions: A, B, and C, with a ratio of $2:3:7$. The pie chart shown below represents this distribution, where the central angle corresponding to region A is °.
60
math
6b6f4d5e-b503-40ad-b0f5-7cfd5399d3ee
As shown in the figure, in the right triangle $ABC$, $\angle ACB = 90^\circ$, $D$ is the midpoint of $AB$, and a perpendicular line from point $D$ to $AB$ intersects $AC$ at point $E$. Given $AC = 8$ and $\cos A = \frac{4}{5}$, find $DE$.
$\frac{15}{4}$
math
ddf5bc77-ba8c-4c7b-b9a4-76e552dd181a
There are 3 squares placed as shown in the figure, the areas of the shaded parts are denoted as $S_1$ and $S_2$ respectively, then $S_1:S_2=$.
4:9
math
040dc4cc-93bf-4557-9bd1-bea08e8c5990
The figure shows a square and its inscribed circle. If a grain of rice is randomly thrown into the square, the probability that it lands inside the circle is.
$\frac{\pi }{4}$
math
8b62200b-fab5-459a-88c3-d602557d4678
In the right triangle ABC, ∠BAC = 90°, AB = AC. Perpendiculars BD and CE are drawn from points B and C to a line passing through point A, with feet of the perpendiculars at D and E, respectively. If BD = 3 and CE = 2, then DE =.
5
math
935bee9f-a448-492f-9919-577b8d16866b
As shown in the figure, in the Cartesian coordinate system, the line y=x+b intersects the x-axis at point A and the y-axis at point B. A circular arc is drawn with point A as the center and the length of segment AB as the radius, intersecting the positive half of the x-axis at point C. If AC=$\sqrt{2}$, then the value of b is.
1
math
1c26d650-575f-4383-bd78-af5db7364700
As shown in the figure, in rectangle ABCD, $AB=3$, $AD=2$. With point A as the center and the length of AD as the radius, an arc is drawn intersecting AB at point E. The area of the shaded part in the figure is (the result should be expressed in terms of $\pi$).
$6-\pi$
math
3e372c4c-0e31-4c8a-9ef8-6f84e40548e3
This summer vacation, Xiaoming's family plans to drive from City A to City G. He has planned a route time map, where the numbers on the arrows represent the required time (unit: hours). What is the shortest time needed to travel from City A to City G in hours?
10
math
09f868fa-aa49-4ccb-a77e-8aea6f9872c0
An equilateral triangle, a right triangle, and an isosceles triangle are placed as shown in the figure. Given that the base angle of the isosceles triangle ∠3 = 72°, then ∠1 + ∠2 =
138°
math
8b5c6b6c-b335-4313-8b0e-cc73bba823b2
Squares A$_{1}$B$_{1}$C$_{1}$O, A$_{2}$B$_{2}$C$_{2}$C$_{1}$, A$_{3}$B$_{3}$C$_{3}$C$_{2}$, … are placed as shown in the figure. Points A$_{1}$, A$_{2}$, A$_{3}$, … and points C$_{1}$, C$_{2}$, C$_{3}$, … lie on the line y = x + 1 and the x-axis, respectively. What is the y-coordinate of point B$_{2018}$?
${{2}^{2017}}$
math
f8fe2b82-0c17-441e-bb3d-1f20acfad5d1
In a skewed triangular prism ABC—A$_{1}$B$_{1}$C$_{1}$ with a volume of 9, S is a point on C$_{1}$C. The volume of S—ABC is 2. What is the volume of the tetrahedron S—A$_{1}$B$_{1}$C$_{1}$?
$1$
math
a1820433-865a-4260-b98d-7bc37b13b956
As shown in the figure, the side length of square $$ABCD$$ is $$1$$, and $$M$$ and $$N$$ are points on $$BC$$ and $$CD$$, respectively. If $$\triangle AMN$$ is an equilateral triangle, then the side length of $$\triangle AMN$$ is ___.
$$\sqrt{6}-\sqrt{2}$$
math
5f7a4506-8f4e-4372-a656-bb7ebf037f58
As shown in the figure, river banks AD and BC are parallel, and bridge AB is perpendicular to both banks. From point C, the angle between the ends of the bridge A and B is ∠BCA = 60°, and the length BC is measured to be 7m. Then the length of the bridge AB is ___ m.
7\sqrt{3}
math
f383c147-7858-4dde-8e93-0109b4a263a9
As shown in the figure, to measure the height of a building, from the top of the building $$A$$, the angle of depression to a point $$B$$ on the ground is $$30^{\circ}$$. It is known that the horizontal distance $$BC$$ from this point on the ground to the building is $$\quantity{30}{m}$$. Therefore, the height of the building $$AC$$ is ___ $$\unit{m}$$ (express the result in radical form).
$$10\sqrt{3}$$
math
bba22c44-c302-44c7-99f5-f57b8e485070
As shown in the figure, $$AB$$ and $$CD$$ are two chords of a circle $$O$$ with radius $$a$$. They intersect at the midpoint $$P$$ of $$AB$$, with $$CP=\dfrac{9}{8}a$$ and $$\angle AOP=60^{\circ}$$. Then, $$PD=$$ ___.
$$\dfrac{2}{3}a$$
math
439d0a63-b142-4e03-969e-c41db6a34049
As shown in the figure, point $$A$$ initially is located at the origin on the number line. Now, point $$A$$ is moved as follows: the first time, it moves 1 unit to the right to point $$B$$; the second time, it moves 3 units to the left to point $$C$$; the third time, it moves 6 units to the right to point $$D$$; the fourth time, it moves 9 units to the left to point $$E$$; and so on. How many times at least must the point be moved so that its distance from the origin is no less than 41?
$$41$$
math
1233666f-ce24-4a20-ac6d-52b9a184eb52
Execute the program flowchart as shown in the figure, then the output of $$n$$ is ___.
$$13$$
math
20424627-5a71-40dd-ad5a-5f1b277b83a0
On a plane, if we use a straight line to cut one corner of a square, we cut off a right-angled triangle. As shown in Figure 1, by labeling the side lengths, we get the Pythagorean theorem: $$c^{2}=a^{2}+b^{2}$$. Imagine replacing the square with a cube and changing the cutting line to a cutting plane as shown in Figure 2. In this case, a tetrahedron $$O-LMN$$ with three edges mutually perpendicular is cut from the cube. If $$S_{1}$$, $$S_{2}$$, and $$S_{3}$$ represent the areas of the three side faces, and $$S_{4}$$ represents the area of the cutting plane, through analogy, the conclusion is ___.
$$S_{4}^2=S_{1}^2+S_{2}^2+S_{3}^2$$
math
3c57d216-9145-4968-92fa-3ab48f002329
The three views of a geometric solid are shown in the figure (unit: m). What is the volume of the geometric solid?
$(6 + \pi) m^3$
math
69e1a3b7-b389-4e20-b790-747139befefe
As shown in the figure, use 4 different colors to color the rectangles A, B, C, and D, with the requirement that adjacent rectangles must be colored differently. How many different ways are there to color them?
72
math
0d4a88ea-46eb-4b36-a562-af07b89d25ca
Arrange the terms of the sequence $\left\{ {{2}^{n}} \right\}$ in order as shown in the figure. What is the 15th number in the 11th row?
${{2}^{115}}$
math
a161c439-d028-4440-850c-87213aecc04b
A survey on monthly pocket money was conducted among 100 randomly selected students from a high school. It was found that the monthly pocket money amounts ranged from 50 to 350 yuan. The frequency distribution histogram is shown in the figure. Among these students, the number of students whose monthly pocket money falls within the interval $\left[ 100,250 \right)$ is.
70
math
977ea5eb-cda9-4da1-a399-3cc14abc81df
As shown in the figure, there is a sphere O inside the cylinder O$_{1}$ O$_{2}$. The sphere is tangent to the top and bottom bases and the generatrix of the cylinder. Let the volume of cylinder O$_{1}$ O$_{2}$ be V$_{1}$, and the volume of sphere O be V$_{2}$. The value of $\frac{V_{1}}{V_{2}}$ is
$\frac{3}{2}$
math
c754b98f-bc6b-4ea9-8d65-8c0ca5b92591
As shown in the figure, an equilateral triangle CDE is constructed outside the square ABCD, and line segments AE and BE are connected. What is the measure of ∠AEB in degrees?
30
math
45a952e0-276a-4509-a2e7-424b828d8c82
In the right triangle $\text{Rt}\vartriangle ABC$, $\angle C=90{}^\circ$, $\angle A=30{}^\circ$, and $BC+AB=6\text{cm}$. Find the length of AB in cm.
4
math
8b5da1f2-86b2-4c61-8e81-a2669b2bdca0
As shown in the figure, AB = AC = AD. If ∠BAC = 28° and AD ∥ BC, then ∠D = .
38°
math
dbff000c-4f79-4f4c-b53f-f6c2a2a90a9b
Given the functions $y=f(x)$ and $y=g(x)$ are defined on $[-3,3]$ as even and odd functions, respectively, and their graphs on $[0,3]$ are shown in the figure, then the solution set of the inequality $\frac{f(x)}{g(x)} \ge 0$ on $[-3,3]$ is.
$(-3,-2] \cup (-1,0) \cup (1,2]$
math
6814d392-1dcd-40ea-acde-921718619fcf
In the figure, in quadrilateral ABCD, ∠B = 75°, BC = 4, the circle ⊙O with AD as its diameter intersects CD at point E. Connect OE. Then the area of the shaded region is.
$\frac{\pi }{3}$
math
9c541544-dd6c-47ae-a95c-04b8352ceecc
As shown in the figure, point D is inside triangle ABC, AC = 4, AD = BC = 3, and angles ACB and ADB are supplementary. The maximum value of the sum of the areas of triangles ACD and BCD is.
$\frac{9}{2}$
math
424791d5-87df-4ff7-aef2-d24b867276b8
It is known that the horizontally placed △ABC is obtained by the 'oblique cavalier projection' method as shown in the figure, where $B'O'=C'O'=2$, $A'O'=\sqrt{3}$. What is the area of the original △ABC?
$4\sqrt{3}$
math
2f3145ea-c815-4ca1-991e-757dec905ea6
As shown in the figure, the following is the unfolded diagram of a rectangular prism (unit: $$cm$$). The area of the largest face among the six faces of this rectangular prism is ______ $$cm^2$$.
27
math
f79425fd-5531-49f0-84b9-a3fb32258eef
Execute the following program flowchart. If the input value of $$\epsilon$$ is $$0.25$$, then the output value of $$n$$ is ______.
$$3$$
math
27cfd1bc-3339-408a-b813-a9bb6356cb03
As shown in the figure, in the right triangle $$ABC$$, $$\angle C=90^{°}$$, $$\angle A=60^{°}$$, $$AB=\quantity{2}{cm}$$, the triangle $$ABC$$ is rotated around point $$B$$ to the position of $$\triangle A_{1}BC_{1}$$, and points $$A$$, $$B$$, and $$C_{1}$$ are collinear. The length of the path that point $$A$$ travels is ___.
$$\dfrac{5\pi }{3}\unit{cm}$$
math
640700ab-dd3d-4f3d-b669-3a143175b12c
Place a right-angled triangular board $$OAB$$ with a $$30^{\circ}$$ angle in a Cartesian coordinate system as shown in the figure, with $$OB$$ on the $$x$$-axis. If $$OA=2$$, and the triangular board is rotated $$75^{\circ}$$ clockwise around the origin $$O$$, then the coordinates of the corresponding point $$A'$$ of point $$A$$ are ___.
$$\left ( \sqrt{2},-\sqrt{2}\right ) $$
math
6839123d-9695-4b8f-92a9-d7b84bb49dd3
As shown in the figure, given the spatial quadrilateral $$OABC$$, $$OB=OC$$, and $$∠AOB=∠AOC=\dfrac {π}{3}$$. Then the value of $$cos<\overrightarrow {OA},\overrightarrow {BC}>$$ is ___.
$$0$$
math
26e69a1d-7058-4a55-b1a2-ee945dfdba44
The three views of a geometric solid are shown in the figure. The surface area of the solid is ___.
$$92$$
math
166ab2dd-dc63-4c91-91ed-9613c4c2d32d
As shown in the figure, $$AB$$ and $$CD$$ intersect at point $$O$$. $$\triangle AOC \backsim \triangle BOD$$, $$OC:OD=1:2$$, and $$AC=5$$. What is the length of $$BD$$?
$$10$$
math
9b3a7d29-ef56-4e2d-b96e-53a69a791a6e
As shown in the figure, when $$\triangle AOB$$ is rotated $$45^{\circ}$$ counterclockwise around point $$O$$, it becomes $$\triangle COD$$. If $$\angle AOB=15^{\circ}$$, then the measure of $$\angle AOD$$ is ___.
$$60^{\circ}$$
math
dbc701d5-f72f-423d-a0ff-d1ef60046cfb
In the $$8 \times 8$$ square grid paper shown in the figure, a needle is randomly thrown onto the paper. The probability of hitting the shaded area is ___.
$$\dfrac{1}{8}$$
math
35a4fc6c-8338-4c27-adb6-7552a65da3e8
As shown in the figure, in the right triangle $$ABC$$, $$∠ACB=90^{\circ}$$, $$∠B=15^{\circ}$$, the perpendicular bisector of $$AB$$ intersects $$AB$$ at point $$E$$ and $$BC$$ at point $$D$$. Given that $$BD=13cm$$, then $$AC=$$ ___.
$$6.5cm$$
math
b4608027-b396-4bf6-9a71-5364f9c0742e
As shown in the figure, there is a point A on the graph of the inverse proportion function y = $\frac{k}{x}$ (k ≠ 0). A perpendicular line AP is drawn from A to the x-axis at point P. If the area of triangle AOP, S$_{△}$$_{AOP}$, is 1, then k = .
2
math
60750105-1e9f-44f2-92ed-43a8ab94f591
The German mathematician Leibniz discovered a unit fraction triangle (a unit fraction refers to a fraction with a numerator of $1$ and a denominator that is a positive integer), known as the Leibniz triangle. According to the pattern in the first $6$ rows, the third number from the left in the $7$th row is.
$\frac{1}{105}$
math
9d8bea15-45d0-4f30-b3ef-b8d9c0924f25
The pattern shown in the figure consists of three blades, which can coincide with itself after rotating 120° around point O. If the area of each blade is 4 cm² and ∠AOB = 120°, then the area of the shaded part in the figure is.
4 cm²
math
0d99048d-c249-417d-a44e-c111fb26322c
In the figure, in $\Delta ABC$, $E$ and $D$ are the midpoints of $AB$ and $CE$ respectively, and $S_{\Delta ABC} = 24$. Then $S_{\Delta EDB} =$.
6
math
397330e9-6aa5-4646-8ef7-3f4032345b7c
As shown in the figure, $A,B$ are two points on the sea level, 800m apart. At point $A$, the angle of elevation to the mountain top $C$ is 45°, and $\angle BAD=120°$. Also, at point $B$, $\angle ABD=45°$, where point $D$ is the projection of point $C$ on the sea level. The height of the mountain $CD$ is.
$800(\sqrt{3}+1)\text{m}$
math
4980fe8f-457c-4a6e-b3d4-6f24267952cf
As shown in the figure, a car is driving straight on a city street. At a certain moment, it is exactly 30m in front of the speed detection device A on the opposite side of the road at point C. After 2 seconds, the distance between the car and the speed detection device is measured to be 50m. What is the speed of the car in m/s?
20
math
6a271400-e17d-4091-9d7e-a864875d8041
As shown in the figure, after a geometric body is cut from a cube with edge length $a$, the volume of the remaining part is.
$\frac{5}{6}{{a}^{3}}$
math
0d934e7d-33ac-49c8-bb59-10130ce63bc0
As shown in the figure, in the Cartesian coordinate system, the line $y=ax$ intersects the hyperbola $y=\frac{k}{x} (k > 0)$ at points $A$ and $B$. A perpendicular line is drawn from point $A$ to the x-axis, intersecting at point $C$. Given that the area of triangle $BOC$ is 3, find the value of $k$.
6
math
e1329385-0afb-4cc4-abaa-3d61be020f5d
There is a numerical converter, the principle of which is shown in the following diagram: When the input x=16, the output y equals.
$\sqrt{2}$
math
17105f43-f65d-4ad4-9cfe-11f02b42ec8a
As shown in the figure, in the rectangle OABC, $OA=3$, $OC=4$. Then the coordinates of point B are.
$\left( -4,3 \right)$
math
0cb4d450-3411-4d8e-b767-0fef47433cc0
A supermarket is holding a grand New Year's promotion. Customers who spend over 100 yuan can participate in a lottery activity. The rules are as follows: The customer places a ball of appropriate size at the top of the container shown in the figure. The ball will freely fall and encounter black obstacles 3 times, finally landing in either bag A or bag B, and the customer will receive the prize in the corresponding bag. It is known that each time the ball encounters a black obstacle, the probability of falling to the left or right is $\frac{1}{2}$. If on the day of the event, Xiao Ming spends 108 yuan in the supermarket, according to the rules of the activity, he can participate in the lottery once, then the probability of Xiao Ming winning the prize in bag A is.
$\frac{3}{4}$
math
1d1e1fad-aa75-4f43-bc10-d2af00a49cfd
There is a straight running track between points A and B. Person A and Person B start from A and B respectively at the same time, running towards each other at a constant speed, and Person B's speed is 80% of Person A's speed. When A and B reach B and A respectively, they immediately turn back and run, with A maintaining the same speed and B increasing his speed by 25% (still at a constant speed). The relationship between the distance y (meters) between A and B and the running time x (minutes) is shown in the figure. What is the distance from B when they meet for the second time?
1687.5
math
943ece05-b6d4-4da9-bcba-894d604b58b5
As shown in the figure, both Figure 1 and Figure 2 are composed of 8 identical small rectangles, and the area of the small square (shaded part) in Figure 2 is 1cm². Then the perimeter of the small rectangle is equal to.
16
math