Step-by-step explanation:
To find the probability of selecting a marble with either green or red on it, we can use the principle of inclusion-exclusion.
1. First, we find the total number of marbles with green or red on them:
Total marbles with green = 5
Total marbles with red = 7
Total marbles with both red and green = 5
Total marbles with either green or red = Total marbles with green + Total marbles with red - Total marbles with both red and green
= 5 + 7 - 5
= 7 marbles
2. Then, we find the probability of selecting a marble with either green or red on it:
Probability = (Number of marbles with either green or red) / (Total number of marbles)
= 7 / 13
So, the probability of randomly choosing a marble with either green or red on it is 7/13.