If the price of gasoline increases by 25% and a driver intends to spend only 20% more on gasoline, by how much percent should the driver reduce the quantity of gasoline that he buys? Choose the correct answer.
A) 2 %
B) 3 %
C) 4 %
D) 5 %
E) 6 %

Rationale: "let x be the amount of gasoline the driver buys originally . let y be the new amount of gasoline the driver should buy . let p be the original price per liter . ( 1.25 * p ) y = 1.2 ( p * x ) y = ( 1.2 / 1.25 ) x = 0.96 x which is a reduction of 4 % . the answer is c ."
Answer: C