Given an interest rate of $6\mathrm{.}0$ percent per year, what is the value at date $t=7$ of a perpetual stream of $$700$ payments that begins at date $t=16?$

NOTE: Valuing a perpetuity is easy: $P{V}_p=\frac{C}{r}.$ This equation gives you the value one period before the cash flows start. But in this problem the cash flows don't start in one period, so when you use the present value equation you are actually calculating the value of the perpetuity at time $t=15,$ or one period before the cash flows begin.