If the price of sugar rises from Rs. 10 per kg to Rs. 13 per kg, a person, to have no increase in the expenditure on sugar, will have to reduce his consumption of sugar by  Choose the correct choice from the following answers
A) 15%
B) 20%
C) 23%
D) 30%
E) none
Sol.   Let the original consumption = 100 kg and new consumption = x kg.   So, 100 x 10 = x × 13 = x = 77 kg.   ∴ Reduction in consumption = 23%.   Answer 23%
<result>C</result>
If the price of sugar rises from Rs. 10 per kg to Rs. 13 per kg, a person, to have no increase in the expenditure on sugar, will have to reduce his consumption of sugar by