r19 wrote:

not able to understand why option 1 sufficient? can you explain with example?

Hey mate, see whether the below explanation helps.

Let the initial no of chocolates be N. Let the price per chocolate be P.

Initial revenue = NxP.

Given the increase in price is x% and decrease in the amount of chocolates sold is y%.

New revenue = [(100+x)/100] x [(100-y)/100] x N x P

Question: Whether the new revenue is more than the old revenue?

A) Given x=y.

If x=y=0

New revenue=Old revenue. There is no increase in revenue after the change so new revenue is not more than old revenue. So the answer for question asked is 'no'.

If x=y=Any value other than 0

The new revenue will be lesser than old revenue. So the answer for the question is again 'no'

Hence A is sufficient.

Cheers!