Answer:
1/12
Explanation:
The probability of first choosing a green marble is 1/4, because there is one green and 4 total.
When you don't replace the green marble, the total number of marbles is now 3, and there is one red marble in the bag. So the second probability is 1/3.
These are independent events, so we multiply them together to get
1/4 * 1/3 = 1/12