A certain sum of money amounts to 3 times of itself in 13 years when interest is compounded annually...........

Quantitative Aptitude (MTS) Compound Interest

A certain sum of money amounts to 3 times of itself in 13 years when interest is compounded annually at a certain rate of

interest per annum. In how many years will the initial sum amount to 9 times of itself at the same rate of interest per annum,

also compounded annually?

This questions was previously asked in

SSC MTS 26th July 2022 Shift-1

32 years

26 years

30 years

20 years

- We are dealing with compound interest where a sum becomes 3 times itself in 13 years.

- Let P be the initial principal and (1 + r) be the growth factor with an unknown decimal rate, r.

- The formula for compound interest is: A = P(1 + r)^n, where A is the amount, P is the principal, and n is the number of years.

- Thus, 3P = P(1 + r)^13 ? (1 + r)^13 = 3.

- For the sum to become 9 times, the equation would be: 9P = P(1 + r)^n ? (1 + r)^n = 9.

- We know 9 = 3^2, so (1 + r)^n = (1 + r)^(2*13).

- Therefore, it will take 26 years to amount to 9 times the initial sum.

- Correct answer is Option 2: 26 years.

Submit Error