Question

The price of petrol is increased by 25%. By how much percent should a car owner should reduce his consumption of petrol so that the expenditure on petrol would not increase?

• A. 25%
• B. 30%
• C. 50%
• D. 20%

Answer 1

Answer:

D. 20%

% Reduction in consumption
= [r/ (100 + r) x 100] %
= [25/ (100 + 25) x 100]
= 20%

Alternate method

Assume cost of petrol before increase is Rs.100.
So cost after increase becomes Rs.125
Increase in expenditure is Rs.25.
Therefore, consumption of petrol should decrease by, =(25/125)*100 =20%