Please help !!!

Silastic-LC-10 is a liquid silicon rubber designed to provide high clarity, superior mechanical properties, and short cycle time for high speed manufacturers. One high-volume manufacturer used it to achieve smooth release from molds. The company's projected through would result in silicon costs of $18,000 in year 1 and costs increasing by $3000 per year through year 6. At an interest rate 8% per year, what is the present worth of these costs