Question

let us determine the rate of simple interest in percent per annum if the interest of Rs 500 in 4yrs is Rs 100​

Answer 1

Given :

Principle : ₹500

Simple Interest : ₹100

Time : 4 years

To find :

The rate of interest applied to the loan.

Solution :

Let us fInd the rate of interest by the formula of simple interest.

Rate of interest :

${\sf \dashrightarrow SI = \dfrac{P \times R \times T}{100}}$

${\sf \dashrightarrow 100 = \dfrac{500 \times R \times 4}{100}}$

${\sf \dashrightarrow 100 = \dfrac{2000 \times R}{100}}$

${\sf \dashrightarrow R = \dfrac{100 \times 100}{2000}}$

${\sf \dashrightarrow R = \dfrac{1 \times 100}{20}}$

${\sf \dashrightarrow R = \dfrac{100}{20}}$

${\sf \dashrightarrow R = 5\%}$

Hence, the rate of interest on simple interest is 5%.

$\:$

Verification

${\sf \dashrightarrow SI = \dfrac{P \times R \times T}{100}}$

${\sf \dashrightarrow 100 = \dfrac{500 \times 5 \times 4}{100}}$

${\sf \dashrightarrow 100 = \dfrac{500 \times 20}{100}}$

${\sf \dashrightarrow 100 = \dfrac{500 \times 1}{5}}$

${\sf \dashrightarrow 100 = \dfrac{500}{5}}$

${\sf \dashrightarrow 100 = 100}$

${\sf \dashrightarrow LHS = RHS}$