Original practice · fully worked
Original variant: infer annual yield from a spaced arithmetic perpetuity
A perpetuity pays 10 at year 3, 20 at year 6, 30 at year 9, and continues increasing by 10 every three years. Its present value is 300. Determine the annual effective yield.
- A
5.00% - B
5.74% - C
6.27% - D
6.75% - E
7.20%
Answer and calculation
The three-year rate solving 300 = 10(1/J + 1/J squared) is 20%. Converting that rate to an annual effective yield gives 6.2659%, choice C.
Setup
Setup
Let J be the effective yield over one three-year payment interval.
300=10(J1+J21) Model
Model
Solve the positive quadratic root.
30J2−J−1=0 Compute
Compute
Convert the three-year rate to an annual effective yield.
i=(1.20)1/3−1=0.0626586 Answer
Answer
The annual yield is 6.27%, choice C.
i≈6.27%(C)