Question

At what percent per annum will Rs. 1000 amount to Rs. 1331 in 3 years than what is the compounded rate of interest per annum?
1. 10%
2. 12%
3. 15%
4. 8%

Answer 1

Correct Answer - Option 1 : 10%

Given:

Principal = Rs. 1000

Amount = Rs. 1331

Time = 3 year

Formula Used:

A = P(1 + R/100)^T

Where,

A = Amount

P = Principal

T = Time

R = Rate

Calculation:

According to question,

A = P(1 + R/100)T

⇒ 1331 = 1000(1 + R/100)³

⇒ (1 + R/100)³ = 1331/1000

⇒ (1 + R/100)³ = (11/10)³

⇒ 1 + R/100 = 11/10

⇒ R/100 = 11/10 - 1

⇒ R/100 = 1/10

⇒ R = 10

∴ The rate of interest per annum is 10%.