Independent solution

How to solve this Annuities question

Setup

Setup

Write payment k as 110 plus k minus 1 copies of the increment.

Pk=110+(k1)XP_k=110+(k-1)X

Model

Model

Value the level and arithmetic-increase components separately.

2000=110a200.10+Xa200.1020v200.102000=110a_{\overline{20}|0.10}+X\frac{a_{\overline{20}|0.10}-20v^{20}}{0.10}

Compute

Compute

The level component is 936.49 and the increment factor is 55.40691, so X = 19.1945.

X=2000936.4920091755.40691159=19.19450047X=\frac{2000-936.49200917}{55.40691159}=19.19450047

Answer

Answer

The annual payment increase is approximately 19.19, selecting choice C.

X19.19(C)\boxed{X\approx19.19\quad\text{(C)}}