In a particular time, a sum becomes 5 times of itself on simple interest at the rate of 15% per annum. What is the rate of interest if the same sum becomes 9 times of itself in the same duration?
Answer & explanation
Correct answer: option 4
Principal : Amount : S.I. ⇒ Rate
5 times ⇒ 1 : 5 : 4 ⇒ 15%
⇓ ×2 ⇓ ×2
9 times ⇒ 1 : 9 : 8 ⇒ 30%