Answer:
R = Pe^(kt) where R = revenue, P is present value, k is interest rate and t is time in years.
(60 000 + 45 000+ 75 000)/2 = Pe^(.07*1)
90 000 = Pe^.07
P = 90 000/e^.07 = $83915.44
(60 000 + 45 000+ 75 000)/2 + 75 000(t-1) = 150 000 e^(kt)
90 000 + 75 000t - 75 000 = 150 000e^(.07t)
15 000 + 75 000t = 150 000e^(.07t)
1/10 + 1/2t = e^(.07t)
ln(.1 + .5t) = .07t
ln(.1+.5t)/t = .07
t = 2.12 years