Question

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?

• A. 90%
• B. 16%
• C. 10%
• D. 96%

Answer 1

Answer:

C. 10%

Let the initial price = 1 and initial consumption = 1
So, initial expenditure = (1 \times 1 = 1)

After increase:

• Price increases by 60% → new price = (1.6)

• Expenditure increases by 44% → new expenditure = (1.44)

Let new consumption = (x)

$\text{New expenditure} = \text{New price} \times \text{New consumption}$
$1.44 = 1.6 \times x$

$x = \frac{1.44}{1.6} = 0.9$

So, consumption becomes 0.9 (i.e., 90% of original)

Reduction in consumption:

$1 - 0.9 = 0.1 = 10\%$
Final Answer:

$\boxed{10\%}$