Pattie's Event Planning Service has just prepared the unadjusted trial balance, which shows the following balances:

Salary expense: Debit $8,000

Service revenues: Credit $3,000

Interest expense: 0

On the first day of January, Pattie borrowed $1,800 on a one-year note payable bearing interest at 4% per year. The note specifies that principal and interest is to be paid in full at the end of the one-year period. On June 30, the adjusted trial balance will show what amount for Interest expense?