Question

A man deposited Rs. 300 for two years, Rs. 600 for 4 years, and Rs. 1200 for 6 years. He received Rs. 102 as interest. What is the rate of interest per annum?

• A. $10\%$
• B. $15\%$
• C. $20\%$
• D. $25\%$

Answer 1

Answer: (A)

$10\%$

Answer 2

1. Calculate weighted interest:

• Multiply each deposit by its time period:$3002 + 6004 + 1200\times6 = 10200$
• Divide this by 100:$\frac{10200}{100}= 102$;
• This directly gives the total interest earned if the rate was$1\%.$

2. Find the rate:

• Since the actual interest is Rs. 102, the rate is simply$\frac{102}{102}= 1$, which is 10%.

The correct answer is (A): $10\%$