On January 1, year 1, ABC. Ltd. purchased a piece of equipment with a cost of $ 180000. The equipment has a useful life of 15 years and a residual value of $ 15000 and is being depreciated under the straight line method. The equipment was sold on April 1. year 5 for $ 170000. Calculate the gain or loss on disposal. If the amount is a gain, enter the answer as a positive amount below (i.e. 20000). If the amount is a loss, enter the answer as negative amount below (i.e. -20000)