Final answer:
The number of different outcomes when choosing 5 marbles from a box of 40 marbles, one at a time without replacement and keeping track of the number of red marbles chosen is 792 (option 1).
Step-by-step explanation:
To find the number of different outcomes when choosing 5 marbles from a box of 40 marbles (20 purple, 12 red, and 8 green), one at a time without replacement and keeping track of the number of red marbles chosen, we can use combinatorial analysis.
The number of ways to choose 5 out of 12 red marbles is given by C(12, 5) = (12!)/(5!(12-5)!) = 792.
Therefore, the correct answer choice is 1) 792.