Profit or loss on disposal

Jack’s year ended is 31 March. He depreciates an office desk at 25% per annum on the straight line basis. A full year’s depreciation is charged in the year an asset is purchased, and no depreciation is charged in the year it is sold. In September 2016, Jack bought an office desk for $90,000.
If he sells the desk for $50,000 in August 2018, what will be Jack’s profit or loss on disposal?

Answer: ????