Paul H. answered 10/16/22
I have taught your college or university course.
The valid outcomes include any sequence of up to and including seven "makes" (I'll use "1" for each) or any single "miss" (I'll use "0" for that).
Then possible sequences for the shots are
0, 10, 110, 1110, 11110, 111110, 1111110,1111111.
Again, by the rule, any 0 stops the game, any 1 and shoot again, until seven Ones. So these are the only possibilities.
The size of the sample space is then EIGHT.