Compound interest

Question

The compound interest for 2 years and 3 years on certain principal at certain rate of interest are Rs 8820 and Rs 9261 respectively. Find the rate of interest and the principal. 

Answer 1

Let the B be the principal r the rate (annual). In 2 and 3 years, respectively, you have

8820=P*r²      <---(1)

9261=P*r³ <---(2)

Now you have to solve for r and P.

Divide (2) by (1): r=9261/8820 find r and then P.

You have to get: r= 1.05, P= 8000. Check it out..

 

Answer 2

8820 = p(1 + r)² ⇒ 8820 / (1 + r)² = p

9621 = p(1 + r)³ ⇒ 9621 / (1 + r)³ = p

 

8829(1 + r)³ = 9621(1 + r)²

 

Can you solve for r and answer?