Dear.
ititle: i need
i need hurry and

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To find out about the outdoor activities, he will need to know specifically about the activities each friend likes 
the answer to the first one is No because the data isn't about how much they do all activities, but just the ones they like the most
The answer to the second is Yes because we need to find out who does what activity and how often that person does that activity
the answer to the third one is No because its counting all activities and we don't need that information
The answer to the 4th one is Yes because we need to know what activity the friends like most
let me know if you need anything else
:)