Activity Selection Problem

#1

I am unable to understand the question. It is little bit confusing.
Plz explain it …

#2

There may be video lectures on Activity Selection concepts in the Greedy Section of your course.You can refer that.
You are given n activities with start and end time, now you need to select the maximum number of activities from them, (you can start another activity only after completing the first activity).
Eg.
4
1 2
5 10
3 4
7 10
Now you can choose 3 activities in the example : 1-2 ,3-4(end time of last and start time of this do not intersect we can choose it), 5 -10 or 7-10 . (we cannot choose both as there time intersects)
Hint:(sort the activities according to end time).