The task is to generate the correct answer for a given math problem.

Input: Consider Input: Problem: pipe a can fill a tank in 6 hours . due to a leak at the bottom , it takes 10 hours for the pipe a to fill the tank . in what time can the leak alone empty the full tank ?

Output: 15


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

Output: 150.84


Input: Consider Input: Problem: 20 men can cut 30 trees in 4 hours . if 4 men leave the job , how many trees will be cut in 6 hours ?


Output: 36