# Assignment On Compound Interest

**SOME PROBLEMR ON COMPOUND INTEREST**

**Rule 1**

If Principal = Rs. P

Time = t years

Rate = r per cent per annum and interest is compounded annually, then

r t

Amount = P 1 + ——

100

Rule 2

If Principal = Rs. P

Time = t years

Rate = r per cent per annum

r nxt

CI (Compound Interest = A – P = P 1 + ——— - 1

100 x n

**Rule 3**

When rate of interest is r1 %, r2 % and r3 % for 1st year, 2nd year, and 3rd year respectively, then Amount = P

r1 r2 r3

1 + —— x 1 + —— x 1 + ——

100 100 100

**Rule 4**

If Principal = P

Rate = r% per annum

Amount = A and

Time is given in the form of fraction like 2½ years.

r

—

r 2 2

Amount (A) = P 1 + ——— x 1 + ———

100 100

**Rule 5**

Theorem : If a certain sum becomes ‘m’ times in ‘t’ years, the rate of compound interest r is equal to 100 [(m)l/t -1].

**SOME PROBLEMS**

1. Amit Kumar invested an amount of Rs. 15000 at compound interest rate of 10 pcpa for a period of 2 years. What amount will he receive at the end of two years?

2. Find the amount at compound interest of Rs. 6325 in 2 years at 4 per cent.

3. Find the compound interest on Rs. 350 for 1 year at 4 per cent compound interest, interest being calculated half yearly.

4. Find the compound interest on Rs. 8000 for 3 months at 5 per cent compound interest payable quarterly.

5. What will be the compound interest acquired on a sum of Rs. 12000 for 3 years at the rate of 10% per annum?