Question

Keshav invests a sum of ₹5400 and Tushar invests a sum of ₹10200 at the same rate of simple interest per annum. If, at the end of 3 years, Tushar gets ₹360 more interest than Keshav, then find the rate of interest per annum (in percentage).

• A. 1.5
• B. 3.5
• C. 2.5
• D. 4.5

Answer 1

Answer:

C. 2.5

Use the simple interest formula:

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

Let the rate be (R%).

Difference in interest after 3 years is ₹360:

$\frac{10200 \times R \times 3}{100} - \frac{5400 \times R \times 3}{100} = 360$

$\frac{(10200 - 5400)\times R \times 3}{100} = 360$

$\frac{4800 \times 3 \times R}{100} = 360$

$144R = 360$

$R = \frac{360}{144} = 2.5$