At the Beginning of the Year,manufacturing Overhead for the Year

Essay

At the beginning of the year,manufacturing overhead for the year was estimated to be $250,860.At the end of the year,actual direct labor-hours for the year were 20,800 hours,the actual manufacturing overhead for the year was $245,860,and manufacturing overhead for the year was underapplied by $10,820.The predetermined overhead rate is based on direct labour-hours.
Required:
What must have been the estimated direct labor-hours at the beginning of the year used in setting the predetermined overhead rate?