context: ###List of Questions
  (1) What is prob of picking 2 s when two letters picked without replacement from {d: 2, n: 2, w: 1, c: 5, f: 2, s: 2}?
  (2) Let k be (3 + 3 + (2 - 23))*-2. Calculate the highest common divisor of 330 and k.
  (3) How many millilitres are there in 12.83532l?
  (4) Divide -1 by 1037.
  (5) Solve -38*s = -53*s - 90 for s.
q_1: (1) What is prob of picking 2 s when two letters picked without replacement from {d: 2, n: 2, w: 1, c: 5, f: 2, s: 2}?
q_2: (2) Let k be (3 + 3 + (2 - 23))*-2. Calculate the highest common divisor of 330 and k.
q_3: (3) How many millilitres are there in 12.83532l?
q_4: (4) Divide -1 by 1037.
q_5: (5) Solve -38*s = -53*s - 90 for s.