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: P can do a work in 24 days. Q can do the samework in 9 days & R can do the same work in 12 days. Q & R start the work and leave after 3 days. P finishes the remaining work in how many days.

 Option A: 8

 Option B: 10

 Option C: 14

 Option D: 16

 Option E: 19

Answer: Option B


Question: Question: If the ratio of a to b is 2 to 3 and the ratio of b to c is 1 to 5, what is the ratio of a to c?

 Option A: 4/15

 Option B: 1/3

 Option C: 2/15

 Option D: 4/5

 Option E: 7/6

Answer: Option C


Question: Question: Insert the missing number
..., 4, 8, 16, 32, 64, 128, 256

 Option A: 6

 Option B: 5

 Option C: 2

 Option D: 3

 Option E: 8

Answer:
Option C