Net Present Value -Unequal Lives

I can't figure out how to calculate the residual value.

Net Present Value-Unequal Lives Project 1 requires an original investment of $68,100. The project will yield cash flows of $18,000 per year for 10 years. Project 2 has a calculated net present value of $16,200 over a eight-year life. Project 1 could be sold at the end of eight years for a price of $69,000. Use the Present Value of $1 at Compound Interest and the Present Vajue of an Annuity of $1 at Compound Interest tables shown below. Determine the net present value of Project 1 over a eight-year life with residual value, assuming a minimum rate of return of 20%. If required, round to the nearest dollar. Which project provides the greatest net present value