At the end of 1st year it depreciates by 15%, so it reduces by 100% - 15% = 85%
At the end of 2nd year it depreciates by 15% again, so it reduces by 100% - 15% = 85%
At the end of 3rd year it depreciates by 15% again, so it reduces by 100% - 15% = 85%
Net Value = 22000 * 0.85 * 0.85 * 0.85 = 13510.75
Value after three years = $13 510.75