Answer:

The cost of truck when the truck is 8 years old is $60,000
Step-by-step explanation:
We are given the following in the question:
Cost of new truck = $140,000
Cost of truck when 9 years old = $41,000
The depreciation is given by the slope of line:

Depreciation value = 10000
The value of truck is given by:

Putting values, we get:

Value of truck at 8 years old:

Thus, the cost of truck when the truck is 8 years old is $60,000