Kingsley Products estimated that direct labor for the year would be 64,320 hours. The company also estimated that the fixed overhead cost for the year would be $160,800. They further estimated the variable overhead cost to be $4.00 per direct labor-hour. All overhead at Kingsley Products is applied on the basis of direct labor-hours. During the year, fixed overhead costs were exactly as planned ($160,800). Variable overhead was incurred at $4.50 per direct labor-hour. Underapplied overhead for the year was calculated as $18,600. Required: How many direct labor-hours were worked during the period? Note: Do not round intermediate calculations