Exam FM technique guide

Annuities and Perpetuities practice problems

Learn how to recognize the method, recall the formulas that control it, and work through 54 sample-question solutions.

Try this original problem before opening the solution. Then compare the method with SOA Exam FM sample question 111.

Original practice · fully worked

Original variant: dividing an orchestra endowment between two programs

An orchestra endowment pays 80 at each year-end forever. The education program receives the first N payments; all later payments support touring. At 4% effective, the touring stream is worth twice the education stream today. Determine N.

  1. A
    8.0
  2. B
    9.0
  3. C
    10.3
  4. D
    12.0
  5. E
    14.0
Show the answer and worked solution

Answer and calculation

The ratio condition gives vᴺ = 2/3 and N = 10.34 years, choice C.

Setup

Setup

Both program values share the same payment amount, so the ratio depends only on the split date and discount factor.

PVE=80aN‾∣,PVT=80vN/iPV_E=80a_{\overline N|},\qquad PV_T=80v^N/i

Model

Model

The later touring payments form a deferred perpetuity, while the education payments form a temporary annuity.

vN1−vN=2⟹vN=23\frac{v^N}{1-v^N}=2\Longrightarrow v^N=\frac23

Compute

Compute

The ratio two reduces to v raised to N equal to two-thirds; logarithms give 10.338.

N=ln⁡(2/3)ln⁡(1/1.04)=10.338N=\frac{\ln(2/3)}{\ln(1/1.04)}=10.338

Answer

Answer

Thus the required split is about 10.3 years, choice C.

N≈10.3(C)\boxed{N\approx10.3\quad\text{(C)}}

Calculator reproduction

BA II Plus keystrokes

  1. 2nd CLR TVM; 2nd I/Y; 1 ENTER; ↓; 1 ENTER; 2nd CPT; 2nd PMT; if BGN is displayed, 2nd ENTER; 2nd CPT; 1 +/- PV; 0 PMT; 1.5 FV; 4 I/Y; CPT NN = 10.338END mode; I/Y is annual. The factor 1.5 is the reciprocal of the derived discount factor two thirds.

Technique orientation

What annuities and perpetuities questions are testing

An annuity formula is a compressed cash-flow diagram. Its value depends on the payment dates, the valuation date, and the effective rate per payment period—not on the label attached to the financial story. Write the first and last payment times before choosing an annuity-immediate, annuity-due, deferred, varying, or perpetuity factor.

Exam FM frequently changes payment frequency, growth pattern, or deferral while leaving the underlying equation of value familiar. Level streams can often be checked on a BA II Plus TVM worksheet; irregular or varying streams are safer as an explicit sum or cash-flow worksheet. In both cases, the analytic timeline controls the calculator inputs.

Recognition audit

Signals that this is the right method

  1. A finite sequence of level payments starts one period after valuation or immediately at valuation.
  2. The first payment is deferred, so the standard factor must be moved from its natural valuation date.
  3. Payments increase arithmetically or geometrically and must be decomposed or valued as a varying stream.
  4. Payments continue indefinitely, making convergence and the relationship between growth and interest essential.

Before calculation

A disciplined first pass

Name the requested quantity, mark its units or time point, and identify the assumption that permits the formula. Only then insert the numerical inputs. This separates model errors from arithmetic errors and makes the answer-choice comparison auditable.

Formula core

Annuities and Perpetuities formulas to know

These identities are starting points, not substitutes for checking support, timing, rate periods, or independence assumptions.

Level annuity-immediate

an‾∣=1−vni,sn‾∣=(1+i)n−1i,v=(1+i)−1a_{\overline{n}|}=\frac{1-v^n}{i},\qquad s_{\overline{n}|}=\frac{(1+i)^n-1}{i},\qquad v=(1+i)^{-1}

The present-value factor sits one period before the first payment; the accumulated-value factor sits at the final payment date.

Annuity-due

a¨n‾∣=(1+i)an‾∣,s¨n‾∣=(1+i)sn‾∣\ddot{a}_{\overline{n}|}=(1+i)a_{\overline{n}|},\qquad \ddot{s}_{\overline{n}|}=(1+i)s_{\overline{n}|}

Moving every payment one period earlier multiplies present value by 1 + i.

Level and growing perpetuities

a∞‾∣=1i,PVgrowing=P1i−g(i>g)a_{\overline{\infty}|}=\frac{1}{i},\qquad PV_{\text{growing}}=\frac{P_1}{i-g}\quad(i>g)

P₁ is the payment one period after valuation; a payment at valuation must be handled separately.

Three failure modes to catch

  • Selecting annuity-immediate when the first payment occurs at the valuation date.
  • Discounting a deferred factor by the number of payments rather than by the number of periods before its natural valuation date.
  • Using an annual quoted rate directly when payments occur monthly, quarterly, or semiannually.

Verified practice ledger

Exam FM annuities and perpetuities problems and solutions

The list is grouped by current official syllabus area. Every link opens a step-labeled solution, verification artifact, distractor analysis, and one fully worked original variant.

Annuities and Non-contingent Cash Flows

54 verified references

  1. SOA Exam FM Sample Question #111Annuities and PerpetuitiesVerified
  2. SOA Exam FM Sample Question #113Annuities and PerpetuitiesVerified
  3. SOA Exam FM Sample Question #114Annuities and PerpetuitiesVerified
  4. SOA Exam FM Sample Question #115Annuities and PerpetuitiesVerified
  5. SOA Exam FM Sample Question #116Annuities and PerpetuitiesVerified
  6. SOA Exam FM Sample Question #117Annuities and PerpetuitiesVerified
  7. SOA Exam FM Sample Question #118Annuities and PerpetuitiesVerified
  8. SOA Exam FM Sample Question #119Annuities and PerpetuitiesVerified
  9. SOA Exam FM Sample Question #120Annuities and PerpetuitiesVerified
  10. SOA Exam FM Sample Question #121Annuities and PerpetuitiesVerified
  11. SOA Exam FM Sample Question #122Annuities and PerpetuitiesVerified
  12. SOA Exam FM Sample Question #123Annuities and PerpetuitiesVerified
  13. SOA Exam FM Sample Question #160Annuities and PerpetuitiesVerified
  14. SOA Exam FM Sample Question #164Annuities and PerpetuitiesVerified
  15. SOA Exam FM Sample Question #169Annuities and PerpetuitiesVerified
  16. SOA Exam FM Sample Question #170Annuities and PerpetuitiesVerified
  17. SOA Exam FM Sample Question #171Annuities and PerpetuitiesVerified
  18. SOA Exam FM Sample Question #173Annuities and PerpetuitiesVerified
  19. SOA Exam FM Sample Question #174Annuities and PerpetuitiesVerified
  20. SOA Exam FM Sample Question #175Annuities and PerpetuitiesVerified
  21. SOA Exam FM Sample Question #178Annuities and PerpetuitiesVerified
  22. SOA Exam FM Sample Question #179Annuities and PerpetuitiesVerified
  23. SOA Exam FM Sample Question #182Annuities and PerpetuitiesVerified
  24. SOA Exam FM Sample Question #233AnnuitiesVerified
  25. SOA Exam FM Sample Question #236AnnuitiesVerified
  26. SOA Exam FM Sample Question #237AnnuitiesVerified
  27. SOA Exam FM Sample Question #238AnnuitiesVerified
  28. SOA Exam FM Sample Question #242AnnuitiesVerified
  29. SOA Exam FM Sample Question #244AnnuitiesVerified
  30. SOA Exam FM Sample Question #245AnnuitiesVerified
  31. SOA Exam FM Sample Question #253AnnuitiesVerified
  32. SOA Exam FM Sample Question #254AnnuitiesVerified
  33. SOA Exam FM Sample Question #259AnnuitiesVerified
  34. SOA Exam FM Sample Question #261AnnuitiesVerified
  35. SOA Exam FM Sample Question #262AnnuitiesVerified
  36. SOA Exam FM Sample Question #276AnnuitiesVerified
  37. SOA Exam FM Sample Question #277AnnuitiesVerified
  38. SOA Exam FM Sample Question #278AnnuitiesVerified
  39. SOA Exam FM Sample Question #285AnnuitiesVerified
  40. SOA Exam FM Sample Question #286AnnuitiesVerified
  41. SOA Exam FM Sample Question #298AnnuitiesVerified
  42. SOA Exam FM Sample Question #302AnnuitiesVerified
  43. SOA Exam FM Sample Question #309AnnuitiesVerified
  44. SOA Exam FM Sample Question #310AnnuitiesVerified
  45. SOA Exam FM Sample Question #313AnnuitiesVerified
  46. SOA Exam FM Sample Question #316AnnuitiesVerified
  47. SOA Exam FM Sample Question #386Annuities and PerpetuitiesVerified
  48. SOA Exam FM Sample Question #392Annuities and PerpetuitiesVerified
  49. SOA Exam FM Sample Question #393Annuities and PerpetuitiesVerified
  50. SOA Exam FM Sample Question #395Annuities and PerpetuitiesVerified
  51. SOA Exam FM Sample Question #396Annuities and PerpetuitiesVerified
  52. SOA Exam FM Sample Question #397Annuities and PerpetuitiesVerified
  53. SOA Exam FM Sample Question #398Annuities and PerpetuitiesVerified
  54. SOA Exam FM Sample Question #403Annuities and PerpetuitiesVerified

Continue the study loop

Keep every worked reference in one searchable manual

The complete Exam FM manual includes all active sample-reference solutions, their wrong-choice analysis, and one independently written worked variant per reference. The free formula sheet is the compact companion for recall between practice sessions.

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