The price (per litre) of petrol increases by 90%. By what percent should its consumption be reduced such that the expenditure on it increases by 33% only?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 30% .
Let original price = 100 and original consumption = 100 units
New price = 100 + 90% of 100 = 190
Let new consumption = x units
Expenditure increases by 33% → New expenditure = 100 + 33 = 133
Expenditure = Price × Consumption
190 × x = 133 × 100 = 13300
x = 13300 ÷ 190 = 70
Reduction in consumption = 100 − 70 = 30%