instruction:
You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.
question:
Question: The least number of complete years in which a sum of money put out at 20% C.I. will be more than doubled is?

 Option A: 3

 Option B: 4

 Option C: 9

 Option D: 3

 Option E: 5
answer:
Option B


question:
Question: A and B together can do a work in 3 days. If A alone can do it in 12 days. In how many days can B alone do it?

 Option A: 4

 Option B: 6

 Option C: 8

 Option D: 10

 Option E: 25
answer:
Option A


question:
Question: A sports equipment store sold ping pong rackets for a total of $637. If the average (arithmetic mean) price of a pair of rackets is $9.8, how many pairs were sold?

 Option A: 50

 Option B: 100

 Option C: 65

 Option D: 500

 Option E: 980
answer:

Option C