Hector puts a principal of $5,600 in a savings account with a simple interest rate of 8%. After several years, he withdraws the balance of $11,424. How many years did he leave his investment in this particular savings account?
The account balance resulting from a principal of P and an interest rate of r over t years is  A = P(1 +rt) Substitute the given values and solve for t.  11424 = 5600(1 + .08t)  (11424/5600) -1 = .08t  1.04/.08 = t = 13
