How long will it take a sum of money invested at 5\% p.a. S.I. to increase its value by 40\%?
(a)5 years
(b)6 years
(c)7 years
(d)8 years
Answer
Answer (as printed): D
Explanation
Let the sum be $x$. Then, S.I. $=40 \%$ of $x=\frac{2 x}{5}$; Rate $=5 \%$. $\therefore \quad$ Time $=\left(100 \times \frac{2 x}{5} \times \frac{1}{x \times 5}\right)=8$ years.
Explanation as extracted from the printed page; notation may be imperfect.