Question

Rakesh rented out an amount to Samarth for 6 years at simple interest rate. At the end of the 6th year, Samarth paid 8/7 of the amount to Rakesh to clear out the amount. The rate of simple interest per annum was :

• A. 2 7/21 %
• B. 2 3/20 %
• C. 2 1/12%
• D. 2 8/21%

Answer 1

Answer:

D. 2 8/21%

Let the principal be (P).

Samarth pays back:
$\frac{8}{7}P$

So, total amount after 6 years:
$A = \frac{8}{7}P$
Simple Interest

$SI = A - P = \frac{8}{7}P - P = \frac{1}{7}P$

Use SI formula

$SI = \frac{P \times R \times T}{100}$

Here:

• (T = 6)

• $(SI = \frac{1}{7}P)$

So,
$\frac{1}{7}P = \frac{P \times R \times 6}{100}$

Cancel (P):
$\frac{1}{7} = \frac{6R}{100}$

Solve for (R)

$6R = \frac{100}{7}$

$R = \frac{100}{42} = \frac{50}{21}$

$R = 2 \frac{8}{21}\%$