Question

If a principal amount of $\$350$ is lent for a time of $2.5$ years earns an interest of $\$140$, then the percentage rate of interest is $\%$.

Answer 1

Given: Principal amount $\left(P\right)=\$350$
Rate of interest $\left(R\right)=?$
Simple Interest $\left(SI\right)=\$140$
Time $\left(T\right)=2.5$ years
We know: $SI=\frac{P\times R\times T}{100}$

$\Rightarrow 140=\frac{350\times R\times 2.5}{100}$

$\Rightarrow R=\frac{140\times 100}{350\times 2.5}=16\%$ per annum