determine

If $2,560 was recieved in january for services performed in January, whag was the balance in unearned revenue at december 31,2018?

The following is a partial trial balance from the books of Hendrix Corporation at January 31, 2019, Credit Debit 1,120 3,840 Account Supplies Prepaid Insurance Salaries and Wages Payable Unearned Revenue Service Revenue Supplies Expense Insurance Expense Salaries and Wages Expense 1,280 1,200 3,200 1,520 640 2,880