I have posted every possible formula to this equation for depreciaiton. For example, 210,000 / 360 months.... or by using the depreciation value of 16800 and I'm still not getting the right answer. What am I doing wrong?

Prepaid Rent Supplie:s Building Accumulated Depreciation-Building 42,000 18,000 210,000 16,800 If the income statement were prepared using trial balance amounts, the net income would be $95,560 A review of the company's records reveals the following information: 1. Rent of $42,000 was paid on July 1, 2019, for 12 months. 2. Purchases of supplies during the year totaled $18,000. An inventory of supplies taken at year-end showed supplies on hand of $2,720 3. The building was purchased three years ago and has an estimated life of 30 years. 4. No adjustments have been made to any of the accounts during the year