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

Hector left his investment for 13 years.