Using the rule of 72. approximate the following: (a)If the value of land in an area is increasing 2 percent a year, how long will it take for property values to double? (Round your answer to 1 decimal place.) Time period years (b)lf you earn 15 percent on your investments, how long would it take for your money to double? (Round your answer to 1 decimal place.) Time period years (c) At an annual interest rate of 4 percent, how long would it take for your savings to double? (Round your answer to 1 decimal place.) Time period years