On July 1, 2015 Mayco purchases a $40,000 truck. Straight line depreciation was calculated on the assumption of a 5 year life and a salvage value of $10,000. At the end of February 2018, the Mayco determine that the truck is no longer needed and it is sold for $20,000 in cash. a) What is the net book value of the truck immediately prior to the disposition b) Prepare the journal entry for the disposal of the truck