A truck was purchased for $120,000 and it was estimated to have a $24000 salvage value at the end of its useful life. Monthly depreciation expense of...

A truck was purchased for $120,000 and it was estimated to have a $24000 salvage value at the end of its useful life. Monthly depreciation expense of $2000 was recorded using the straight line method. The annual depreciation rate is 25%.

I under stand the first part of the question by doing 120,000-24,000= 96000 but i don't understand how to get the percentage rate.