Question

Varun invests a sum of ₹5400 and Ashish invests a sum of ₹9400 at the same rate of simple interest per annum. If, at the end of 3 years, Ashish gets ₹960 more interest than Varun, then find the rate of interest per annum (in percentage).

• A. 8
• B. 10
• C. 7
• D. 6

Answer 1

Answer:

A. 8

Let rate = (r%) per annum.

Simple Interest:

$SI = \frac{P \times r \times t}{100}$

Time (t = 3) years

Difference in interests:

$SI_{Ashish} - SI_{Varun} = 960$

$\frac{9400 \cdot r \cdot 3}{100} - \frac{5400 \cdot r \cdot 3}{100} = 960$

Take common terms:
$\frac{3r}{100}(9400 - 5400) = 960$

$\frac{3r}{100} \cdot 4000 = 960$

120r = 960

$r = 8$

Final Answer: 8% per annum