Question

Vijay invests a sum of ₹5400 and Mohan invests a sum of ₹9400 at the same rate of simple interest per annum. If, at the end of 4 years, Mohan gets ₹360 more interest than Vijay, then find the rate of interest per annum (in percentage).

• A. 3.50
• B. 2.25
• C. 4.75
• D. 5.25

Answer 1

Answer:

B. 2.25

Let the rate of interest = (r%)

Simple Interest formula

$\text{SI} = \frac{P \times r \times t}{100}$
Interest for Vijay and Mohan

• Vijay:
  $\frac{5400 \times r \times 4}{100}$

• Mohan:
  $\frac{9400 \times r \times 4}{100}$

  Difference in interest

$\frac{(9400 - 5400)\times r \times 4}{100} = 360$
$\frac{4000 \times r \times 4}{100} = 360$

$\frac{16000r}{100} = 360$

160r = 360

$r = \frac{360}{160} = 2.25$
Final Answer: 2.25% per annum