Question

Pravin has ₹1612 with him. He divided it amongst his sons Rishi and Shan and asked them to invest it at 8% rate of interest compounded annually. It was seen that Rishi and Shan got same amount after 17 and 18 years respectively. How much (in ₹) did Pravin give to Rishi?

• A. 687
• B. 775
• C. 875
• D. 837

Answer 1

Answer:

D. 837

Let Rishi’s share be x, so Shan’s share is 1612 − x.

Given:

• Both amounts become equal at compound interest

• Rate = 8% annually

  Use compound interest equality

$x(1.08)^{17} = (1612 - x)(1.08)^{18}$

Divide both sides by $((1.08)^{17})$

$x = (1612 - x)(1.08)$

Solve equation

$x = 1612 \times 1.08 - 1.08x$
$x + 1.08x = 1612 \times 1.08$
$2.08x = 1740.96$
$x = \frac{1740.96}{2.08}$
$x = 837$

Final Answer: ₹837