Maths of F4 standard

A cleaning company, which provides office and home cleaning, has 2 full-time workers and 4 part-time workers. It is known that each office cleaning requires 8 man-hours, while each home cleaning requires 4 man-hours. It is the company policy that office cleanings should be conducted by full-time workers. Suppose a full-time worker works for 8 hours a day and a part-time worker works 4 hours a day. Let x and y be the daily numbers of office and home cleaning services provided by the company respectively.

Write down all the constraints on x and y.