On January $1,$ year $1,$ ABC. Ltd$.$ purchased a piece of equipment with a cost of $ $200000.$ The equipment has a useful life of $15$ years and a residual value of $ $10000$ and is being depreciated under the straight line method. The equipment was sold on October $1,$ year $5$ for $ $80000.$

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$.-20000).$