In how many years will a sum of money double itself at 12.5% p.a., at…

The correct answer is Option (4) → 8 years

Under simple interest, the interest is the same every year. A sum doubles when the total interest equals the principal.

Assuming the principal to be 100:

• Interest needed \(=100\) (the amount becomes 200)

• Interest each year at 12.5% \(=12.5\)

• Years \(\displaystyle =\frac{100}{12.5}=8\)