Chapter 8.9, Problem 59E

Perpetual annuity Imagine that today you deposit $B in a savings account that earns interest at a rate of p% per year compounded continuously (Section 6.9). The goal is to draw an income of $I per year from the account forever. The amount of money that must be deposited is $B=I{\displaystyle {\int }_0^{\infty }{e}^{-rt}dt}$, where r = p/100. Suppose you find an account that earns 12% interest annually and you wish to have an income from the account of $5000 per year. How much must you deposit today?