Question

# A certain sum amount 12167 in 3 years at 15% p.a compounded annually. Find sum.

Hint: Here we go through by putting the formula of amount as we read in chapter compound interest because we have to find the sum i.e. principal amount and at the end of three years total amount is given i.e. certain sum.

Let us apply the formula of amount in which rate is compounded annually i.e. $A = P{\left( {1 + \dfrac{R}{{100}}} \right)^T}$
$\Rightarrow 12167 = P{\left( {1 + \dfrac{{15}}{{100}}} \right)^3} \\ \Rightarrow 12167 = P{\left( {\dfrac{{23}}{{20}}} \right)^3} \\ \Rightarrow P = \dfrac{{12167 \times 20 \times 20 \times 20}}{{23 \times 23 \times 23}} \\ \Rightarrow P = Rs.8000 \\$