How to get this calculation? Thank you

Bellward Company grants vacation time of two weeks to those employees who have worked for the company one complete year. After 10 years of service, employees receive four weeks of vacation. The monthly payroll for January totals $320,000, of which 70% is payable to employees with 10 or more years of service. On January 31 , record the January expense arising from the vacation policy of the company. (Round the final answers to the nearest whole dollar.)