Independent solution

How to solve this Arithmetic-Increasing Perpetuity with Multi-Year Spacing question

Setup

Setup

Convert the 6% annual yield to an effective rate per three-year payment interval.

J=(1.06)31=0.191016J=(1.06)^3-1=0.191016

Model

Model

At three-year intervals the payments are X, 2X, 3X, and so on.

PV=Xk=1kvJkPV=X\sum_{k=1}^{\infty}kv_J^k

Compute

Compute

Use the arithmetic-perpetuity identity.

655.56=X(1J+1J2)655.56=X\left(\frac1J+\frac1{J^2}\right)
X=20.08327X=20.08327

Answer

Answer

The first payment is approximately 20, choice C.

X20(C)\boxed{X\approx20\quad\text{(C)}}