Question

in the new budget the price of petrol Rose by 10% by how much percent must one reduce the consumption so that the expenditure does not increase

Answer 1

Here is the answer

lets assume initial 1 liter petrol cost=100
10% increase=100+10/100*100=110(that is 1 liter petrol cost is increased)
expenditure is same.that means we should buy the petrol only for 100 rupees.
increased amount of petrol is rs.10. that means this rs.10 is the part of amount in rs.110
now,
we should find what is the percentage of rs.10 in rs.110(because if you remove this rs,10,then you will get the same expenditure)
=10/110*100=9.09%
so 9% of consumption should be reduced.
please mark me brainliest

Answer 2

Answer

Let price of petrol be Rs.100.

After increasing,

Price of petrol =100+

100

10

×100=Rs.110

Now, to keep same expenditure, the consumption should be reduced by x%(say).

Now,

x=

110

110−100

×100

⇒x=

110

10

×100≈9%

Hence, to keep same expenditure, the consumption should be reduced by 9%.

Still not clear? Check out the attachment please.