The price of sugar is decreased by 30%. By what percentage should a man increase his consumption so that his expenditure remains the same?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → \(42\frac{6}{7}\%\)
Expenditure \(=\) price \(\times\) consumption. For the expenditure to stay the same, the consumption must rise in the opposite ratio to the price, and the increase is measured on the old consumption.
Price goes from 100 to 70
Consumption must go from 70 to 100
Increase \(\displaystyle =\frac{30}{70}\times100=\frac{300}{7}=42\frac{6}{7}\%\)
He should increase his consumption by \(42\frac{6}{7}\%\).