context: ###List of Questions
  (1) Let f = -4 + 15. What is the units digit of f - (-3 - (-3)/3)?
  (2) What is prob of sequence fo when two letters picked without replacement from {o: 2, f: 1, n: 2, u: 4}?
  (3) In base 13, what is -4b + 10?
  (4) How many months are there in five eighths of a millennium?
  (5) Suppose -4*t + 1 - 5 = 0, 3*t + 3 = 5*r. Suppose -3*a = a - 52. Solve -2*s + s - a = -4*c, -2*s + 5*c - 17 = r for s.
q_1: (1) Let f = -4 + 15. What is the units digit of f - (-3 - (-3)/3)?
q_2: (2) What is prob of sequence fo when two letters picked without replacement from {o: 2, f: 1, n: 2, u: 4}?
q_3: (3) In base 13, what is -4b + 10?
q_4: (4) How many months are there in five eighths of a millennium?
q_5: (5) Suppose -4*t + 1 - 5 = 0, 3*t + 3 = 5*r. Suppose -3*a = a - 52. Solve -2*s + s - a = -4*c, -2*s + 5*c - 17 = r for s.