# Simple Interest

- Final amount is principal plus interest, A = P +I
- Simple interest is given by
**I = (P × R × T)/100**

## Exercise

- Find the simple interest on Rs 40000 at 7½% per annum for 3 years 3 months.
- Find the rate of interest when Rs 800 amounts to Rs 930 in 2½ years.
- Find the time when simple interest on Rs 3.3 lakhs at 6.5 per annum is Rs 75075.
- Find the principal amount when

(a) simple interest at 7¼% per annum for 2½ years is Rs 2356.25

(b) final amount is 11300 at 4% per annum for 3¼ years. - Sukhram borrows Rs 6000 to purchase a cow and clears his debt by paying
Rs 8000 after 4 months. Find the rate of interest charged per annum.

[**Hint.**4 months = 4/12 years = 1/3 years]. - A man borrowed Rs 1500 on 1st April and returned Rs 1572 on 13th June. Find the rate of interest charged.
- A farmer purchased a cow by borrowing at 10% per annum simple interest. If he borrowed money on 22nd April and returned the money on 4th July along with an interest of Rs 120, find the money borrowed.
- A man invested Rs 2000 at a rate of interest of 1 paisa per rupee per month. What amount will he get after 4 months?
- The interest on a sum of money at the end of 5 years is 3/5th of the sum. Find the rate of interest.
- Rs 4050 amounts to Rs 4576.50 in 2 years. At same rate of interest, how much would Rs 1 lac amount to in 3 years?

## Answers

**1.**Rs. 9750

**2.**6.5% per annum

**3.**3½ years

**4.**(a) Rs 13000 (b) Rs 10000

**5.**100% per annum

**6.**24% per annum

**7.**Rs 6000

**8.**Rs 2080

**9.**12% per annum

**10.**Rs 119500