If the price of petrol increases by 35% and Benson intends to spend only an additional 15% on petrol, by how much % will he reduce the quantity of petrol purchased?
15%
Let the price of petrol be ‘x’ and Benson purchases ‘y’ litres of petrol
Therefore, he would have spent Rs.xy
New price per litre of petrol =35x100+x=135x100=1.35x
Benson williing to spend = xy + 15% of xy = 1.15xy
Let the new quantity of petrol that he can get be ‘q’
q = 1.15xy1.35x=1.15y1.35=0.85y
As the new quantity that he can buy is 0.85y, he gets 0.15y lesser than what he used to get earlier.
Or a reduction of 0.15*100 = 15%