A veterinarian depreciates a $10,000 X-ray machine. He estimates that the resale value V(t) (in $) after t years is 90% of its value from the previous year. Therefore, the resale value can be approximated by V(t) = 10,000(0.9)^t.

a. Find the resale value after 3 yr.

b. If the veterinarian wants to sell his practice 10 yr after the X-ray machine was purchased, how much is the machine worth? Round to the nearest $100.