Shreya lends 40% of a certain sum at 15%p.a. 50%of the rest sum at 10%p.a. and the rest at 18%p.a rate of interest. What would be the rate of interest if the interest is calculated on the whole sum?

A. 13.4%p.a.

B. 14.33%p.a.

C. 14.4%p.a.

D. 13.33%p.a.

Answer: Option C

Solution(By Examveda Team)

Let lending amount is Rs 100
First 40 % interest is 40 x 15% = 6
Next 30% interest is 30 x 10% = 3
Last 30% interest is 30 x 18% = 5.4
Total Interest = 14.4
Percentage = 14.4/100 x 100= 14.4%