Question

If the compound interest on sum of Rs. $29000$ for $2$ years is Rs. $9352.5$ Find the rate of interest.

• A. $11$
• B. $9$
• C. $15$
• D. $18$

Answer 1

The correct option is C $15$

Given, $P=$ Rs. $29000$, time $=2$ years, C.I. $=$ Rs. $9352.5$

Amount $=$ Principal $+$ C.I.

$\Rightarrow 29000+9352.5=$Rs. $38352.5$

We know, $A=P{(1+\frac{R}{100})}^t$

$\Rightarrow 38352.5=29000{(1+\frac{R}{100})}^2$

$\Rightarrow {(1+\frac{R}{100})}^2=\frac{38352.5}{29000}$

$\Rightarrow {(1+\frac{R}{100})}^2=\frac{13225}{10000}$

$\Rightarrow {(1+\frac{R}{100})}^2={\left(\frac{115}{100}\right)}^2$

$\Rightarrow 1+\frac{R}{100}=\frac{115}{100}$

$\Rightarrow \frac{100+R}{100}=\frac{115}{100}$

$\Rightarrow R=115-100$

$\Rightarrow R=15\%$

Therefore, rate of interest is $15\%$.