Definition: 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.
Input: 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
Output:
Option C