A delivered price $($including attachments$)$ of a crawler dozer tractor is $$135,000$ with a residual value of $35\%.$ The useful life of the tractor is $7,700$ hours.

a$.$ What is total amount of depreciation allowed?

Total amount

What is the amount of depreciation per hour?

Note: Round your answer to the nearest cent.

Amount of depreciation $($per hour$)$

$.$ If the tractor is operated five days a week for an average of $7\mathrm{.}25$ hours a day, what would be the depreciation for the first year?

Depreciation for the first year

If the hours of operation were the same each year, what would be the total number of years of useful life for the tractor?

Note: Round "years" to the nearest whole number.

Total number of years