Independent solution

How to solve this Monthly Contributions Funding an Annual Perpetuity question

Setup

Setup

Convert the 1% monthly rate to an annual effective rate.

ia=(1.01)121=0.12682503i_a=(1.01)^{12}-1=0.12682503

Model

Model

The first perpetuity payment coincides with the last contribution, so value a perpetuity-due at time 5.

F5=5,0001+iaia=44,424.3943F_5=5{,}000\frac{1+i_a}{i_a}=44{,}424.3943

Compute

Compute

Accumulate sixty month-end contributions to that same time.

Xs600.01=44,424.3943Xs_{\overline{60}|0.01}=44{,}424.3943
s600.01=81.6696699s_{\overline{60}|0.01}=81.6696699

Answer

Answer

The monthly contribution is 543.95, choice D.

X=543.9522544(D)\boxed{X=543.9522\approx544\quad\text{(D)}}

Calculator reproduction

BA II Plus keystrokes

Check END/BGN, period, sign, TVM, and cash-flow setup

  1. 60 · N; 1 · I/Y; 0 · PV; 44424.3943 · +/− · FV; CPT · PMT543.95END mode matches contributions at month-ends.