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

Ex Input:
Problem: by selling an article at rs . 600 , a shopkeeper makes a profit of 25 % . at what price should he sell the article so as to make a loss of 25 % ?

Ex Output:
s . 360


Ex Input:
Problem: if x = 1 + √ 2 , then what is the value of x 4 - 4 x 3 + 4 x 2 + 3 ?

Ex Output:
4


Ex Input:
Problem: joe invested a certain sum of money in a simple interest bond whose value grew to $ 310 at the end of 3 years and to $ 410 at the end of another 5 years . what was the rate of interest in which he invested his sum ?

Ex Output:

8 %