A machine which cost $720,000 is acquired on February 1, 2017. Its estimated salvage value is $75,000 and its expected life is 12 years.

1. Calculate depreciation expense for 2017 and 2018 by each following methods, showing the figures used.

(a) Double-declining balance

(b) Sum-of-the-years'-digits

2. At the end of 2018, which method results in the larger accumulated depreciation amount?