Correct Answer - Option 2 : 33.1%
Formula used :
CI = Principle × (1 + r/100)t – Principle
Amount = P × (1 + r/100)t
Interest = PTR/100
CALCULATION :
Suppose Pi and Ii denote the principal at the beginning of the ith year, respectively.
Given : P6 = 110% of P5
⇒ P6 = 1.1P5
We know that P6 = (1 + r) P5
∴ r = 0.1
Now, I9 = r × P9
I12 = r × P12
Where, P12 = (1 + r)3 × P9
⇒ I12 = r × (1 + r)3 × P9
Therefore,
I12 : I9 = [r(1 + r)3 × P9] : [r × P9]
⇒ I12 : I9 = (1 + r)3 : 1
⇒ I12 : I9 = (1 + 0.1)3 : 1
⇒ I12 : I9 = 1.331
Hence, I
12 is 33.1% more than I
9.