context: ###List of Questions
  (1) Let c = -4 - -7. Let q(r) = r**2 + 4. What is the tens digit of q(c)?
  (2) How many micrometers are there in 36.01521 nanometers?
  (3) Multiply -18 and 0.13.
  (4) What is prob of sequence wu when two letters picked without replacement from {i: 3, w: 2, q: 7, u: 3}?
  (5) What comes next: -81, -90, -111, -150, -213, -306?
q_1: (1) Let c = -4 - -7. Let q(r) = r**2 + 4. What is the tens digit of q(c)?
q_2: (2) How many micrometers are there in 36.01521 nanometers?
q_3: (3) Multiply -18 and 0.13.
q_4: (4) What is prob of sequence wu when two letters picked without replacement from {i: 3, w: 2, q: 7, u: 3}?
q_5: (5) What comes next: -81, -90, -111, -150, -213, -306?