It would be log(81) because of the power rule...
Present value, P = 20
compounding interest per 6 months, i = 0.025/2 = 0.0125
Number of periods, n = 30*2 = 60 (half-years)
Future value in 30 years
=P(1+i)^n
=20(1.0125)^60
= $42.14
Parallel lines and midpoint of a segment
This should be the answer