# Compound Intrest

## Vedic Maths trick to find Compound Intrest

### Simple Interest

Simple Interest = S.I.
Principal = P
Rate Of Interes = R
Time = T
Amount = A

1) S.I. = A - P

2) S.I. = P * R * T / 100

### Compound Interest

Compound Interest = C.I.
Principal = P
Rate Of Interes = r
Time = n
Amount = A

1) C.I. = A - P

2) A = P [ 1 + r / 100 ]n

3) C.I. = A - P
C.I. = P [ 1 + r / 100 ]n - P
C.I. = P [ (1 + r / 100 )n - 1 ]

### Compound Interest If Time Is In Mix Number

If time = 3 1/2 then

A = P [ 1 + r / 100 ]3 - [ 1 + r/2 / 100]

Here for half year we will multiply 2 in time that is (1/2 * 2 = 1) and divide the rate of interest by 2 that is (r / 2).

If time = 2 1/4 then

A = P [ 1 + r / 100 ]2 - [ 1 + r/4 / 100]

Here for 1/4 year we will multiply 4 in time that is (1/4 * 4 = 1) and divide the rate of interest by 4 that is (r / 4).

### Compound Interest If Rate Of Interest Are Different

Rate Of Interest = First year is 10% & Second year is 12%

Let r1 = 10% & r2 = 12%

A = P [ 1 + r1 / 100 ] [ 1 + r2/ 100]