Question

Vipul invests a sum of INR 5400 and Vijay invests a sum of INR 9400 at the same rate of simple interest per annum.If, at the end of 5 years , Vijay gets INR 840 more interest than Vipul, then find the rate of interest per annum. (in percentage).

• A. 6.2
• B. 3.2
• C. 2.2
• D. 4.2

Answer 1

Answer:

D. 4.2

Let the rate of simple interest = R% per annum.

Vipul’s principal $(P_1 = 5400)$

Vijay’s principal $(P_2 = 9400)$

Time (T = 5) years

Difference in interest = ₹840

Simple Interest formula:

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

Difference of interests:

$\frac{9400 \times R \times 5}{100} - \frac{5400 \times R \times 5}{100} = 840$

$\frac{(9400 - 5400) \times R \times 5}{100} = 840$

$\frac{4000 \times R \times 5}{100} = 840$

$200R = 840$

$R = \frac{840}{200} = 4.2$
rate of interest = 4.2% per annum