Answer:
see below
Explanation:
The car will have some value. It will not decrease to nothing
We take 1/3 away from the value each year
This means we keep 2/3 of the value
Year 0 value 18000
Year 1 value 18000 *2/3
Year 2 value 18000 * 2/3 * 2/3
Year 3 value 18000 * 2/3 * 2/3 * 2/3
Year 6 value 18000 * 2/3 * 2/3 * 2/3* 2/3 * 2/3 * 2/3
value 18000 * 2/3 ^6
Year t value = 18000 * 2/3 ^ t
v = 18000 * 2/3 ^t