If the price of petrol is increased by 20%, by what percentage should the consumption be decreased by the consumer, if the expenditure on petrol remains unchanged?
Correct Answer: 162/3
Explanation:
Required decrease in consumption = [a/(100 + a)] x 100%
= [20/(100 + 20)] x 100%
= (20/120) x 100%
= 162/3%
