Compound Intrest

Vedic Maths trick to find Compound Intrest

A sum of money at compounded interest double it self in 2 years .In how many years will it amount to 8 times it self.

Let a sum( P ) for 2 years = Amount ( 2P )

Putting the value in Compound intrest formula:

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

P [ 1 + r / 100 ]2 = 2P

[ 1 + r / 100 ]2 = 2

8 times can be written as:

8 times = 8P = (2)3P

[ [ 1 + r / 100 ]2 ]3 = (2)3

[ 1 + r / 100 ]6 = (2)3

The sum will be 8 times in 6 years