please help with the problem step by step explanations please

1. The following data is available for the Cleaning Services Department of Maxwell Co. $216,000 168,000 Revenues Cost of Sales ........... Expenses: Supplies-Direct.... Salaries-Indirect Allocated Rent-Direct Rent-Indirect Allocated............. 12,000 34,000 8,000 4,500 Required: Calculate departmental contribution to overhead for the Cleaning Services Department, including the department's contribution as a percentage of revenues