context: ###List of Questions
  (1) Calculate prob of picking 1 a and 1 g when two letters picked without replacement from aaag.
  (2) What is (-2)/3*69/253?
  (3) How many decades are there in 148722.75 months?
  (4) What is the units digit of (-33)/(-7) - 2/(-7)?
  (5) Let a(z) = -2*z - 14. Let t be a(-7). Solve t*r + 2*r - 4*h + 10 = 0, 5*r - 3*h + 18 = 0 for r.
q_1: (1) Calculate prob of picking 1 a and 1 g when two letters picked without replacement from aaag.
q_2: (2) What is (-2)/3*69/253?
q_3: (3) How many decades are there in 148722.75 months?
q_4: (4) What is the units digit of (-33)/(-7) - 2/(-7)?
q_5: (5) Let a(z) = -2*z - 14. Let t be a(-7). Solve t*r + 2*r - 4*h + 10 = 0, 5*r - 3*h + 18 = 0 for r.