Independent solution

How to solve this Reinvestment of Interest Cash Flows question

Setup

Setup

Each 1000 deposit remains principal; each completed year generates 40 of interest per prior deposit.

principal at year 30=30(1,000)=30,000\text{principal at year 30}=30(1{,}000)=30{,}000

Model

Model

At the end of year m+1 there are m interest-producing deposits. Reinvest that interest for the remaining years.

I30=40m=129m(1.03)29mI_{30}=40\sum_{m=1}^{29}m(1.03)^{29-m}

Compute

Compute

The reinvested interest is 23433.8876.

AV30=30,000+23,433.8876=53,433.8876AV_{30}=30{,}000+23{,}433.8876=53{,}433.8876

Answer

Answer

The accumulated value rounds to 53434, choice B.

53,434(B)\boxed{53{,}434\quad\text{(B)}}