If the price of gasoline increases by 25% and Ron intends to spend only 15% more on gasoline, by what % should he reduce the quantity of petrol that he buys?

1 Answer
Jul 26, 2016

Answer:

8%

Explanation:

Suppose Ron buys quantity of gasoline today #=x#
Let today's price of gasoline be equal to #=y#
Ron spends on gasoline today #=xy#

The new price of gasoline is (increase by #25%#)#=1.25xxy#
Ron wants to spend only #15%# more,
#:. #he wants to spend#=1.15xxxy#
Quantity he buys at new rate#=(1.15xxxy)/(1.25xxy)=(1.15x)/(1.25)#
Reduction in quantity of purchase#=x-(1.15x)/(1.25)=(0.10x)/1.25#
% Reduction in quantity of purchase of gasoline #=((0.10x)/1.25)/x xx100#
#=0.10/1.25 xx100=8%#