Saving number rules

1. Rule of 72
    Number of years takes to double the money = 72/Interest
    Eg. 72/8= 9 years ( So in 9 years with 8% interest rate your money might double)
2. Rule of 114
    Number of years takes to triple the money = 72/Interest
    Eg. 114/8= 14.25 years ( So in 14.25 years with 8% interest rate your money might triple)
3. How much net worth you should have
    Age * Pre-tax income
   ------------------------ = Net worth
                10