Question

I invested 120 in a surprise scheme. I was returned 180 after a year. What was rate of

simple interest on my investment?​

Answer 1

Answer:

• Rate of simple interest is 50% p.a.

Step-by-step explanation:

Given that:

• Principal = Rs 120
• Amount = Rs 180
• Time = 1 year

To Find:

• Rate of simple interest.

Concept:

• For finding the rate of simple interest first we have to find the simple interest after that we will able to find the rate of interest.

Formula used:

1. S.I. = A - P
2. S.I. = (P × R × T)/100

Where,

• S.I. = Simple interest
• A = Amount
• P = Principal
• R = Rate
• T = Time

Finding the simple interest:

⟿ S.I. = 180 - 120

⟿ S.I. = 60

∴ Simple interest = Rs 60

Finding the rate of interest:

⟿ 60 = (120 × R × 1)/100

⟿ 60 × 100 = 120R

⟿ 120R = 6000

⟿ R = 6000/120

⟿ R = 50

∴ Rate of interest = 50% p.a.

Answer 2

Answer:

Rate of interest is 50 % per annum.

Step-by-step explanation:

Given :-

A person invested 120 in a surprise scheme. He was returned 180 after a year.

To find :-

Rate of simple interest on his investment.

Solution :-

Here,

Principal = 120

Amount = 180

Time period = 1

Simple interest = Amount - Principal

• 180 - 120
• 60

Simple interest = Principal × Time × Rate of interest/100

• 60 = 120 × R × 1/100
• 60 = 120R × 1/100
• 60 × 100 = 120R
• 6000 = 120R
• R = 6000/120
• R = 50

∴ Rate of interest is 50 % per annum.