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

Ex Input:
Problem: how many liters of a 40 % iodine solution need to be mixed with 35 liters of a 20 % iodine solution to create a 34 % iodine solution ?

Ex Output:
13

Ex Input:
Problem: what is the greatest prime factor of 2 ^ 10 - 1 ?

Ex Output:
3

Ex Input:
Problem: raman mixed 48 kg of butter at rs . 150 per kg with 36 kg butter at the rate of rs . 125 per kg . at what price per kg should he sell the mixture to make a profit of 40 % in the transaction ?

Ex Output:
195