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

[Q]: 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 ?
[A]: c ) 30

[Q]: Problem: a retailer buys 80 pens at the market price of 36 pens from a wholesaler , if he sells these pens giving a discount of 1 % , what is the profit % ?
[A]: 12

[Q]: Problem: if x + y = 20 , x - y = 36 , for integers of x and y , x = ?
[A]:
28