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

Problem: a circular ground whose diameter is 70 metres , has a 2.8 metre - broad garden around it . what is the area of the garden in square metres ?
640.64

Problem: one half of a two digit number exceeds its one third by 7 . what is the sum of the digits of the number ?
e ) 1

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 % ?
12