Consider the following operating and maintenance costs of a new machine whose first cost is $ 86,000 with a useful life of 6 years and its salvage value is $ 14,000 whatever its age is. The interest...

Consider the following operating and maintenance costs of a new machine whose first cost is $ 86,000 with a useful life of 6 years and its salvage value is $ 14,000 whatever its age is. The interest rate is 6%, compounded annually. Find its economic life.