A = P (1 + r/n)^t
A = 100,000
r = 8% = 0.08
compounded semiannual so, n = 2
t = (18 - 5) = 13 years
And for semiannual , t = 13 * 2 = 26
so,
100,000 = P * ( 1 + 0.08/2)^26
100,000 = P * ( 1 + 0.04)^26
100,000 = P * 2.77247
P = 100,000/2.77247 = 36,068.92
So, the amount of money to the nearest dollar = $36,069