This Exam FM sample reference tests Annuities. An arithmetic perpetuity with first payment 150 and annual increment 10 has value 150/i + 10/i². Setting this equal to 5,000 gives positive root 6.22%, so choice B is correct.
These notes identify the calculation error associated with each wrong letter when that error is reproducible.
AChoice A (5.7%) does not satisfy the arithmetic-perpetuity price equation 5000 = 150/i + 10/i²; no distinct standard one-step error is identifiable.
CChoice C (6.7%) does not satisfy the arithmetic-perpetuity price equation 5000 = 150/i + 10/i²; no distinct standard one-step error is identifiable.
DChoice D (7.2%) does not satisfy the arithmetic-perpetuity price equation 5000 = 150/i + 10/i²; no distinct standard one-step error is identifiable.
EChoice E (7.7%) does not satisfy the arithmetic-perpetuity price equation 5000 = 150/i + 10/i²; no distinct standard one-step error is identifiable.
Original practice · fully worked
Original variant: annual arithmetic increment supported by a fixed perpetuity price
An annual perpetuity-immediate is priced at 25,000 using a 4% annual effective yield. Its first payment is 500, and every later payment exceeds the preceding payment by K. Calculate K.
A 18.00
B 19.00
C 20.00
D 21.00
E 22.00
Variant answer in brief
The 500 level component is worth 12,500. The remaining 12,500 equals K divided by 4% squared, giving annual increment 20.00, choice C.
Setup
Setup
Write the arithmetic perpetuity as a level-payment part plus an increasing part.
25000=0.04500+(0.04)2K
Model
Model
Remove the level component and multiply the residual price by the square of the yield.
K=(0.04)2(25000−0.04500)
Compute
Compute
The resulting annual increment is 20.0000.
K=20.00000000
Answer
Answer
Each payment increases by 20.00, selecting choice C.
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