context: ###List of Questions
  (1) How many decades are there in one fifth of a century?
  (2) Suppose -16 = 4*q - 0*q. Let z be (-50)/q + (-1)/(-2). Suppose -2*a + 37 = -67. Calculate the greatest common factor of z and a.
  (3) Solve -8*y = -7*y + 5*y for y.
  (4) What is 6 + (-2 - 2) - -5?
  (5) What is prob of picking 1 k and 1 t when two letters picked without replacement from ttktktttktttkw?
q_1: (1) How many decades are there in one fifth of a century?
q_2: (2) Suppose -16 = 4*q - 0*q. Let z be (-50)/q + (-1)/(-2). Suppose -2*a + 37 = -67. Calculate the greatest common factor of z and a.
q_3: (3) Solve -8*y = -7*y + 5*y for y.
q_4: (4) What is 6 + (-2 - 2) - -5?
q_5: (5) What is prob of picking 1 k and 1 t when two letters picked without replacement from ttktktttktttkw?