In a certain time, a sum becomes 4 times at the rate of 5% per annum. At what rate of simple interest, the same sum becomes 8 times in the same duration?
Correct Answer: 112/3 %
Explanation:
Let the sum be p
Then, for R = 5%
SI = (4p - p) = 3p
∴ 3p = (P x 5 x T)/100 = PT/20
⇒ T = 60 yr Again, for another rate (R)
SI = (8P - P) = 7P
∴ 7P = (P x R x 60)/100
⇒ R = (7 x 100)/60 = 35/3%
= 112/3 %