Exchange Rates - GCSE Higher Question

This Maths problem has been taken from a Higher GCSE Paper.

Nancy goes to the post office to exchange money

Exchange Rates £1.00: $1.31 £1.00: €1.14 Commission Charged

Nancy changes $759.80 and €342 into pounds sterling The Post Office deducts their commission and gives Nancy £827.20 What is the percentage commission?