Question

the consumption of petrol by Mr. kumar's car dropped from 100 litres a month to 85 litres a month with 20%hike in petrol prices

Answer 1

Answer:

16.66% or 16.67%

Step-by-step explanation:

If the price of petrol increases by 20%, by what percent should Mr. Brown reduce his consumption of petrol so that his expenditure on petrol remains the same?

To elaborate by an example, consider the cost of petrol as 70 rupees/ litre and Mr. Brown refills only 70 rupees petrol, no matter the increase or decrease in price.

Now if the cost is increased to 20% it will be

= 70+(20%*70)

=84 rupees/ litre.

So the price difference is 84–70=14 rupees/ litre.

Now if the expenditure should be same so that Mr. Brown will pay only 70 rupees, then he must be consuming less petrol. ( i.e lesser than 1 litre.). So he will consume :

i.e (70 rupees / 84 rupees)*1 litre= 0.8333 litre.

Reduction in quantity of petrol consumed by Mr. Brown= 1 litre –0.83333 litre= 0.1666 litre.

Therefore percentage reduction of petrol consumption by Mr. Brown

=(1–0.8333)*100= 16.67 %

OR

Simply (14/84)*100 = 16.66 %