Question

Question 1 - In the new budget, the price of petrol rose by 10%. By how much per cent must one reduce the consumption so that the expenditure does not increase?

Answer 1

Solution :-

Let the initial price of petrol be Rs. x

Then, price after increase of 10 % = 100 + (100*10)/100

= 100 + 10

Price after increase of 10 % = Rs. 110

Now,

Reduction in consumption of petrol in percent = [{(110 - 100)}*100]/110

⇒ (10*100)/110

⇒ 100/11

⇒ 9.09 % (approximately 9%)

So, the motorists have to reduce the consumption of petrol by 9.09 %(approximately 9%), so that the expenditure on it remains unchanged.