Accounting hw help double declining balance?

On January 13, 2010, Silverio Oil Company purchased a drilling truck for $45,000. Silverio expects the truck to last five years or 200,000 miles, with an estimated residual value of $7,500 at the end of that time. During 2011, the truck is driven 48,000 miles. Silverio's year end is December 31. what is the depreciation for 2011 under the double declining balance method?