** Simple and Compound Interest Formula**P - Principal, the sum of money lent or borrowed. .

R - Rate of interest: Annual interest, often expressed as a percentage. .

T - Time period for which the money is lent or borrowed. .

Simple Interest = Principal * Time * Rate of interest / 100 .

SI = 4000× 8% × 4 = 4000× 0.08 × 4.

= 1280. .

In compound interest , the principal amount with interest after the first time period becomes the part of principal for the next time period.

CI = [P (1 + R/100)^T] – P .

Total amount = [P (1 + R/100)^T] .

If time period is half-yearly, .

Amount = P[1 + (R/2)/100]^2T .

If time period is quarterly, .

Amount = P[1 + (R/4)/100...

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