Ryder Incorporated costs its products using job order costing. The following represents the company's work in process account activity and balances for the month of July. Manufacturing overhead is applied to production using a predetermined overhead rate, using direct labour cost as the cost driver.

Work in Process Account
Balance, July 1	-0-
Direct materials	20,000
Direct labour	30,000
Manufacturing overhead	60,000
Transferred out		95,000
Balance, July 31	15,000

Job 378 was the only job in process at the end of the month. This job had been charged with $3,000 in direct materials cost.

Required: a. Complete the following job order cost card for Job 378.

Direct materials	$3,000
Direct labour	_______
Manufacturing overhead	_______
Total cost at July 31	_______

b. Determine the total amount of materials cost that was charged to completed jobs during the month.