context: ###List of Questions
  (1) Calculate 72 divided by 3.
  (2) Let j be (-141)/(-21)*1 + (-4)/(-14). What is the highest common divisor of j and 14?
  (3) How many grams are there in 3764.978 micrograms?
  (4) Suppose -6*m = -m. Let c(d) = 2*d + 5. Let w be c(m). Solve -4*a - 20 = 5*r, -3*r - w*a = -a + 12 for r.
  (5) Three letters picked without replacement from bbvyybbvybvyy. Give prob of picking 1 v and 2 b.
q_1: (1) Calculate 72 divided by 3.
q_2: (2) Let j be (-141)/(-21)*1 + (-4)/(-14). What is the highest common divisor of j and 14?
q_3: (3) How many grams are there in 3764.978 micrograms?
q_4: (4) Suppose -6*m = -m. Let c(d) = 2*d + 5. Let w be c(m). Solve -4*a - 20 = 5*r, -3*r - w*a = -a + 12 for r.
q_5: (5) Three letters picked without replacement from bbvyybbvybvyy. Give prob of picking 1 v and 2 b.