The formula for annually compounded interest is as follows:
[tex] A = P(1 + r)^t [/tex]
P is the initial amount you invest, r is the interest rate as a decimal, and t is the number of years the money will have been invested.
Convert the 8% interest rate into a decimal by dividing by 100:
[tex] 8 \div 100 = 0.08 [/tex]
We now have all of our values. Plug the known values into the equation:
[tex] P = 500, r = 0.08 [/tex]
[tex] t = 20 [/tex]
[tex] 500(1+0.08)^{20} = 500(1.08)^{20} = \boxed{2330.48} [/tex]
[tex] t = 50 [/tex]
[tex] 500(1+0.08)^{50} = 500(1.08)^{50} = \boxed{23450.81} [/tex]