What is the 15*15*15 Rule in Mutual funds?
15 X 15 X 15 rule of mutual funds
One of the most often discussed rule in Mutual Funds is 15*15*15 Rule, the rule in simple terms is that if one does a Systematic Investment Plan SIP of Rs 15000 per month in a mutual fund for 15 years which earns average 15% compounded annual returns, then You are able to accumulate Rs 1 Crore. And your total investment amount is only Rs 27 lakhs.
15 X 15 X 30 rule of mutual funds
If you do a Rs 15,000 SIP per month for 30 years (instead of 15 years as earlier), at a 15% compounded annual return, You will be able to accumulate Rs 10 crores against 1 crore if you invest for 15 years.
Means Rs 15000 * 360 Months = Rs 54 lakhs.

Rule Of 72 :
What is the ‘Rule of 72’ ?
The rule of 72 is a shortcut to estimate the number of years required to double your money at a given annual rate of return. The rule states that you divide the rate, expressed as a percentage, into 72:
The rule of 72 is a useful shortcut, since the equations related to compound interest are too complicated for most people to do without a calculator. To find out exactly how long it would take to double an investment that returns 8% annually, one would have to use this equation:
Numbers of years = 72/8 = 9 years.