The task is to generate the correct answer for a given math problem.
--------
Question: Problem: a bag contains 12 red marbles . if someone were to remove 2 marbles from the bag , one at a time , and replace the first marble after it was removed , the probability that neither marble would be red is 25 / 36 . how many marbles are in the bag ?

Answer: 48


Question: Problem: find the cost of fencing around a circular field of diameter 16 m at the rate of rs . 3 a meter ?

Answer: 150.84


Question: Problem: adam borrowed some money at the rate of 6 % p . a . for the first two years , at the rate of 9 % p . a . for the next 3 years , and at the rate of 14 % p . a . for the period beyond 5 years . 1 £ he pays a total interest of rs . 11400 at the end of 9 years how much money did he borrow ?

Answer:
rs . 1200