Question

The price (per litre) of petrol increases by 50%. By what percent should its consumption be reduced such that the expenditure on it increases by 14% only?

• A. 77%
• B. 76%
• C. 29%
• D. 24%

Answer 1

Answer:

D. 24%

Let original price = 1, original consumption = 1
⇒ Original expenditure = 1

New price = +50% ⇒ 1.5
Let new consumption = (x)

New expenditure = (1.5x)

Given expenditure increases by 14%:
1.5x = 1.14

$x = \frac{1.14}{1.5} = 0.76$

So consumption becomes 76% of original.

Reduction = (100 - 76 = 24%)

Answer: 24% reduction