If I give you Rs. 1,00,000. In how much time you can double it if the rate of interest is 6%.
You will take about 10 minutes to calcuate this, but there is a simpler method to calculate the time to double your money. Simply divide 72 by rate of interest.
Number of years required to double money = 72/ Annual rate of interest
In above case rate of interest is 6% thus it will take 72/6= 12 years to double itself.
Just try yourself.