The price (per litre) of petrol increases by 60%. By what percent should its consumption be reduced such that the expenditure on it increases by 44% only?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 10%.
Let original price = 100, original consumption = 100
New price = 100 + 60% = 160
Let new consumption = x
Expenditure change = (New price × New consumption) / (Original price × Original consumption) = 1 + 44% = 1.44
So, (160 × x) / (100 × 100) = 1.44
(160x) / 10,000 = 1.44
160x = 14,400
x = 14,400 / 160 = 90
Consumption reduced from 100 to 90 → reduction = (100 - 90)% = 10%