Preferre room to multiples activities in one step

[llantones]

The example in the manual is:
An activity is splitted into 4 activities per week. Only one of these activities need the computer lab and not the home room.
My question is:
An activity is splitted into 4 activities per week. The 4 activities need the computer lab.

How make it in one step? I only know make it by the 4 activities.

One suggestion: When I add a activitie, that I can add the preferred room.

Thanks

[Volker Dirr]

Do it like in the manual, first example:

Subject chemistry must always be instructed in the chemistry lab.
Add constraint A subject has a preferred room if you have just one chemistry room.
Add constraint A subject has a set of preferred rooms if you have several chemistry rooms.

or like the 3th example:

Subject biology must always be instructed in biology lab in year 7 to 10, but must not be instructed in year 5 and 6.
Set an activity tag to all biology activities that need a room (so all biologie activites of year 7 to 10). Add constraint A subject+activity tag have a preferred room with weight 100%. Add constraint A subject has a preferred room with weight under 100%.

[llantones]

Thank's for your answer. My English is so bad that I couldn't find it.

[llantones]

Could it be easier to add: A activity tag  has a preferred room and then set an activity tag to the activity I add?