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.

[EX Q]: Question: The radius of a semi circle is 6.3 cm then its perimeter is?

 Option A: 32.9

 Option B: 32.4

 Option C: 32.2

 Option D: 32.1

 Option E: 32.7
[EX A]: Option B

[EX Q]: Question: If the number 5 * 2 is divisible by 6, then * = ?

 Option A: 2

 Option B: 5

 Option C: 3

 Option D: 1

 Option E: 6
[EX A]: Option A

[EX Q]: Question: 2 pipes can separately fill a tank in 20hrs and 30hrs respectively. Both the pipes are opened to fillthe tank, a leak develops in the tank through which one-third of water supplied by both the pipes goes out. What is the total time taken to fill the tank?

 Option A: 10 hrs

 Option B: 12 hrs

 Option C: 16 hrs

 Option D: 18 hrs

 Option E: 20 hrs
[EX A]:
Option C