Question

The simple interest on rupees 400 for 2 years is rupees 40 then the rate of interest is?​

Answer 1

As per the data given in the question,

We have to determine the rate of interest.

As per question,

It is given that,

Principal = Rs. 400

Time = 2 years

SI = Rs. 40

As we know that,

From the formula of Simple Interest,

We have,

$SI = \frac{PRT}{100}$

So, let the rate percentage = r%

So, from above formula,

We will get,

$40 = \frac{400\times 2 \times r}{100}\\=>r = \frac{40\times 100}{400\times 2}\\=>r = \frac{4000}{800}\\=>r\% = 5\%$

Hence, value of rate percentage will be 5%.

Answer 2

Given: $P=Rs.400, T=2 years, and SI=Rs.40$

We have to find the rate of interest.

As we know that the formula is used to calculate the simple interest is:

$S I=\frac{P R T}{100}$

We are solving in the following way:

$P=Rs.400, T=2 years, and SI=Rs.40$

By putting the above value in the formula we get:

$S I=\frac{P R T}{100}$

$\begin{array}{l}\Rightarrow 40=\frac{400 \times 2 \times r}{100} \\\\\Rightarrow r=\frac{40 \times 100}{400 \times 2} \\\\\Rightarrow r=\frac{4000}{800} \\\\\Rightarrow r \%=5 \%\end{array}$

Hence, the rate of interest will be$5\%$.