Question

Mukund invests a sum of ₹5400 and Sachin invests a sum of ₹9400 at the same rate of simple interest per annum. If, at the end of 4 years, Sachin gets ₹960 more interest than Mukund, then find the rate of interest per annum (in percentage).

• A. 5
• B. 4
• C. 6
• D. 8

Answer 1

Answer:

C. 6

We use Simple Interest formula:
$SI = \frac{P \times R \times T}{100}$

Write interest for both

Mukund:
$SI_M = \frac{5400 \times R \times 4}{100}$

Sachin:
$SI_S = \frac{9400 \times R \times 4}{100}$

Difference in interest

Given:
$SI_S - SI_M = 960$
$\frac{4R}{100}(9400 - 5400) = 960$

$\frac{4R}{100} \times 4000 = 960$

Solve

$\frac{16000R}{100} = 960$

160R = 960

$R = \frac{960}{160} = 6$

Final Answer: 6%