Question

The price of petrol increased by 25% and a person decreased the consumption of petrol by 15%. What will be the percentage change in his expense on petrol?

• A. 10% increase
• B. 6.25% increase
• C. 7.5% decrease
• D. No change

Answer 1

The correct option is B 6.25% increase

Let us assume the price of petrol to be Rs.100 per unit and the consumption of the person to be 100 units of petrol.

So, the initial expense was 100 × 100 = Rs.10000

Now the price increased by 25%, then

The new price = Rs. 125 per unit.

Consumption decreased by 15%, then

The new consumption = 85 units of petrol.

∴Final expense = 125 × 85 = Rs. 10625

Increase in expense = 10625 – 10000 = Rs. 625

So,the percentage increase in expense = $\frac{625}{10000}\times 100=6.25$%

Hence, option B is the correct answer.