Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.
--------
Question: Problem: what will be the compound interest on a sum of rs. 20,000 after 3 years at the rate of 12 % p. a. ?
Options: a. rs. 8098.56, b. rs. 9720, c. rs. 10123.20, d. rs. 10483.20, e. none

Answer: a


Question: Problem: if a and b are positive real numbers, and a ^ 3 + b ^ 3 = 25, then the greatest possible value of a is between :
Options: a. 0 and 3, b. 3 and 4, c. 4 and 5, d. 5 and 7, e. 7 and 9

Answer: a


Question: Problem: a boat having a length 9 m and breadth 3 m is floating on a lake. the boat sinks by 1 cm when a man gets on it. the mass of the man is :
Options: a. 100 kg, b. 120 kg, c. 189 kg, d. 180 kg, e. 270 kg

Answer:
e