A person makes a profit of 10% on 25% of the quantity and a loss of 20% on the rest. What is the percentage gain or loss on the whole?

A 10%

B 12.5%

C -12%

D 25%

Correct Answer: Option B

If whole quantity is 100

10% profit from 25% is = 25*110/100 = 27.5

20% loss from 75% is = 75*80/100 = 60

Total price of selling = 60 + 27.5

= 87.5

We can see that there has been a loss.

Loss is = 100 - 87.5 = 12.5 or 12.5%