Answer:
4.76%
Step-by-step explanation:
The requirement in this question is determining the discount rate which gives the same present value in both cases since discount rates discount future cash flows to present value terms.
PV of a pertuity=annual cash flow/discount rate
PV of a pertuity=$17,000/r
PV of ordinary annuity=annual cash flow*(1-(1+r)^-n/r
PV of ordinary annuity=$30,000*(1-(1+r)^-18/r
$17,000/r=$30,000*(1-(1+r)^-18/r
multiply boths side by r
17000=30,000*(1-(1+r)^-18
divide both sides by 30000
17000/30000=1-(1+r)^-18
0.566666667=1-(1+r)^-18
by rearraging the equation we have the below
(1+r)^-18=1-0.566666667
(1+r)^-18=0.433333333
divide indices on both sides by -18
1+r=(0.433333333)^(1/-18)
1+r=1.047554315
r=1.047554315-1
r=4.76%