Answer:
-$3576
Explanation:
Depreciation using double declining method=100%/useful life*2
Depreciation using double declining method=100%/10*2=20%
2017 depreciation=$60,000*20%=$12000
2018 depreciation=($60,000-$12000)*20%=$9600
2019 depreciation=($60,000-$12000-$9600 )*20%=$7680
2020 depreciation=($60,000-$12000-$9600-$7680 )*20%=$6144
carrying value in 2021=$60000-$12000-$9600 -$7680-$6144 =$24576
Loss on disposal of machine=$21,000-$24576 =-$3576