Howard Corporation has a job order costing system. The following debits (credits) appear in the firm's work in process account for the month of June: June 1, Balance $12 000 June 30, Direct materials $40 000 June 30, Direct labour $30 000 June 30, overhead applied $27 000 June 30, to finished goods ($100 000) Overhead is applied at 90 per cent of direct labour cost. There is only one job still in process at the end of June, and this job has been charged with $2250 factory overhead. What was the amount of direct materials charged to that job? Select one: $2250 $9000 $2500 $4250