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

Ex Input:
Problem: 6 ) a marketing firm determined that , of 260 households surveyed , 80 used neither brand a nor brand b soap . 60 used only brand a soap and for every household that used both brands of soap , 3 used only brand b soap . how many of the 200 household surveyed used both brands of soap ?

Ex Output:
c ) 30


Ex Input:
Problem: the area of a triangle is with base 10 m and height 5 m ?

Ex Output:
25


Ex Input:
Problem: what will be the cost of building a fence around a square plot with area equal to 289 sq ft , if the price per foot of building the fence is rs . 60 ?

Ex Output:

s . 4080