Question

What should be the rate of simple interest if the amount owed after 4 months is rs.1938 borrowed amount being rs.1900

Answer 1

$\textbf{\underline{\underline{Answer :-}}}$

The Rate of interest is 6%

$\textbf{\underline{\underline{Explanation :-}}}$

Given :

Time = 4 months

Amount = 1938

The money borrowed = Rs.1900

To find :

The Rate of interest

Solution :

Here,

Principal = Rs.1900

Amount = Rs.1938

Time = 4 months (⅓)

Simple Interest = Amount - Principal

→ 1938 - 1900

→ 38

Simple Interest (SI) = Rs.38

$\star$ As we know :

${\boxed{\sf\:{SI = \frac{Principal \times Rate \: \times Time}{100} }}}$

$\sf{\implies}38 = \dfrac{1900 \times R \times \frac{1}{3} }{100}$

$\sf{\implies}38 \times 100 = 1900 \times R \times \frac{1}{3}$

$\sf{\implies}3800= 1900 \times R \times \frac{1}{3}$

$\sf{\implies}3800\times 3 = 1900 \times R \times 1$

$\sf{\implies}11400 = 1900 \times R$

$\sf{\implies}R = \dfrac{11400}{1900}$

$\sf{\implies}R = 6$

${\boxed{\bigstar{\sf\:{Rate\% = 6\%}}}}$

$\therefore$ The Rate of interest is 6%

$\textbf{\underline{\underline{Verification :-}}}$

$\sf{\implies}38 = \dfrac{1900 \times 6 \times \frac{1}{3} }{100}$

$\sf{\implies}38 = \dfrac{11400 \times \frac{1}{3} }{100}$

$\sf{\implies}38 = \dfrac{3800}{100}$

$\sf{\implies}38 = 38$

When we place the value of R (6) we got the Simple Interest correct (38)

$\therefore$ The Rate of interest is 6%