Put the verb in brackets into the more suitable form, the present perfect continuous (have been doing) or the present perfect (have done).
— I'm having a party on Saturday.
— (invite) How many people you ?
The present perfect continuous tells us how long the action has been continuing.
The present perfect puts the focus on the result of the action or tells us how many times the action has happened so far.
Jenny is wet and exhausted. She has been running. → the continuing process is important
Jenny has run 10 kilometres today. → the result is important