Refining machine has been acquired at PHP 100,000 expected to be useful for 10 years, and would have a salvage value of PHP 1,500 by then what is the depreciation cost per year (t) of the machine, what is the book value of the machine at the end of year 5 using the Sum of the Years digit method.

1. 28,654

2. 50,000

3. 10,765

4. 71,636