The balance in the Prepaid Rent account before adjustment at the end of the year is $20400, which represents three months rent paid on December 1. The adjusting entry required on December 31 is to debit Rent Expense, $13600; credit Prepaid Rent $13600. debit Prepaid Rent, $13600; credit Rent Expense, $13600. debit Prepaid Rent, 36800: credit Rent Expense, $6800 debit Rent Expense, $6800; credit Prepaid Rent $6800