Question

A sum of rs 8000 becomes rs 12500 in 2 years at a certain rate of compound interest. What will be the sum (in rs) after 3 years?

Answer 1

Let the rate be r.

Principal money=Rs.8000

Time=2 years

Amount=Rs.12500

∴12500=8000(1+   r/100)²

125=80(1+   r/100)²

125/80=(1+  r/100)²

125/80= (100+r/   100)²

125*100*100/80=(100+r)²

125*125=(100+r)²

√125*125=100+r

∴125=100+r

⇒r=125-100=25 %