Question

The price (per litre) of petrol increases by 85%. By what percent should its consumption be reduced such that the expenditure on it increase by 48% only ?

• A. 18%
• B. 82%
• C. 20%
• D. 80%

Answer 1

Answer:

C. 20%

Let the original price per litre = ₹100
Let the original consumption = 100 litres

Original expenditure:

$100 \times 100 = 10000$

After price increase:

Price increases by 85%
New price = (100 + 85 = ₹185)

Let consumption be reduced by x%
New consumption = (100 - x) litres

New expenditure increases by 48%:

$\text{New expenditure} = 10000 + 48$

So,
$185 \times (100 - x) = 14800$
$100 - x = \frac{14800}{185} = 80$

$x = 100 - 80 = 20$

Required reduction in consumption = 20%