Please show solution for this question.

The equipment in the production system has a scrap value of $10,000 and can be used for another 4 years. The cost is as follows.

The equipment 1 year old, saves $5,000 in operating costs and $6,000 in scrap value

The equipment 2 years old, saves $4,000 in operating costs and $4,000 in scrap value

The equipment 3 years old, save $3,000 in operating costs and $2,000 in scrap value

The equipment 4 years old, save $2,000 in operating costs and $0 in scrap value

If MARR=15% per year, do you think this device should be discontinued?

Answer = should not be discontinued.