If the price of petrol increases by 20, by how much must a user cut down his consumption so that his expenditure on petrol remains constant?	Choose the most appropriate option:	A) 16.7 %	B) 20 %	C) 24.67 %	D) 33.33 %	E) none of these

Rationale: "explanation : let us assume before increase the petrol will be rs . 100 . after increase it will be rs ( 100 + 20 ) i . e 120 . now , his consumption should be reduced to : - = ( 120 − 100 ) / 120 ∗ 100 . hence , the consumption should be reduced to 16.7 % . answer : a"
Answer: A