## Compound Interest Shortcut Tricks

**Some important formula of Compound Interest**

- A = Amount.

P = Principal.

R = Rate of Interest.

N = Number of Years.

**Type I : Interest compounded yearly :**

**A = P ( 1 + r / 100 )**^{n}

**Type II : Interest compounded half – yearly :**

Amount =**P [ 1 + r / 2 / 100 ]**or = P =^{4n}**[ 1 + r / 200 ]**^{2n}

**Type III : Interest compounded quarterly :**

Amount =**P [ 1 + r / 4 / 100 ]**or =**P [ 1 + r / 400 ]**^{4n}

In Compound Interest problems asked in exams up to the period of 3 years.

In case we apply basic formula: Amount = Principle ( 1 + r / 100 )^{n} here r = Rate and n = Time

As consider if Principle is Rs. 1, then the it will be in first year and second and third years.

( 1 + r / 100 )^{1}

( 1 + r / 100 )^{2}

( 1 + r / 100 )^{3}

If the rate of interest is 3%, then the value will be …….

In first year = (23 / 21 ) = 23 / 21.

In second year = ( 23 / 21 )^{2} = 529 / 441.

In Third year = ( 23 / 21 )^{3} = 12167 / 9261.