If the compound interest on a certain sum at $16\frac{2}{3}\%$ for 3 years is ₹1270, find the simple interest on the same sum at the same rate and for the same period.
Answer
Answer (as printed):
Explanation
Let the sum be ₹x. Then, C.I. $=\left[x \times\left(1+\frac{50}{3 \times 100}\right)^{3}-x\right]=\left(\frac{343x}{216}-x\right)=\frac{127x}{216}$. ∴ $\frac{127x}{216}=1270$ or $x=\frac{1270 \times 216}{127}=2160$. Thus, the sum is ₹2160. ∴ S.I. $=₹\left(2160 \times \frac{50}{3} \times 3 \times \frac{1}{100}\right)=₹1080$.
Explanation as extracted from the printed page; notation may be imperfect.