The price (per litre) of petrol increases by 70%. By what percent should its consumption be reduced such that the expenditure on it increases by 19% only?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 30 %
Let , original price = P original consumption = C
Original expenditure = P × C
New price = 1.7P
New consumption = C × (1 - x/100)
New expenditure = 1.7P × C × (1 - x/100)
Given new expenditure = 1.19PC
So, 1.7 (1 - x/100) = 1.19
1 - x/100 = 1.19 ÷ 1.7 = 0.7
x/100 = 0.3
x = 30