This Exam FM sample reference tests Annuities. Value the first five payments under 4% growth, then value at time 5 the perpetuity whose next payment reflects the fifth 4% increase and grows 8% thereafter. The two components are 3.87 and 17.26, totaling 21.13; choice A.
These notes identify the calculation error associated with each wrong letter when that error is reproducible.
BChoice B (23.51) does not satisfy the finite 4%-growth block plus the time-5 value of the 8%-growth tail; no distinct standard one-step error is identifiable.
CChoice C (25.95) does not satisfy the finite 4%-growth block plus the time-5 value of the 8%-growth tail; no distinct standard one-step error is identifiable.
DChoice D (28.87) does not satisfy the finite 4%-growth block plus the time-5 value of the 8%-growth tail; no distinct standard one-step error is identifiable.
EChoice E (31.23) does not satisfy the finite 4%-growth block plus the time-5 value of the 8%-growth tail; no distinct standard one-step error is identifiable.
Original practice · fully worked
Original variant: growth-transition date inferred from a perpetuity price
A perpetuity pays 1 at year 1. Payments initially grow 3% annually; after N early payments, all later payments grow 6% annually. At a 10% yield, the price is 22.5222. Determine N.
A 3 payments
B 4 payments
C 5 payments
D 6 payments
E 7 payments
Variant answer in brief
Testing the finite early-growth block together with the later 6%-growth tail shows the quoted price is produced by N = 4 early payments, choice B.
Setup
Setup
For a candidate N, value the first N payments under 3% growth.
PV1(N)=t=1∑N(1.10)t(1.03)t−1
Model
Model
At time N, append the perpetuity tail beginning with the next 3%-grown payment and then growing 6%.
PV2(N)=0.10−0.06(1.03)N(1.10)−N
Compute
Compute
The sum matches the quoted price at N = 4.
PV1(4)+PV2(4)=22.5221892289
Answer
Answer
There are 4 early-growth payments, selecting choice B.
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