Question

Rohan deposited ₹500 for 2 years, ₹650 for 4 years and ₹1,300 for 6 years, at the same rate of interest. He received the total simple interest of ₹1,140. What is the rate of interest per annum?

• A. 10%
• B. 9.5%
• C. 10.5%
• D. 11%

Answer 1

Answer:

A. 10%

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

Compute total $(P \times T)$

• ₹500 for 2 years → $(500 \times 2 = 1000)$

• ₹650 for 4 years → $(650 \times 4 = 2600)$

• ₹1300 for 6 years → $(1300 \times 6 = 7800)$

Total:
$1000 + 2600 + 7800 = 11400$

Apply SI formula

$1140 = \frac{11400 \times R}{100}$

Solve for R

$1140 = 114R$
$R = \frac{1140}{114} = 10$

Final Answer: 10% per annum