Answer:
7/12
Step-by-step explanation:
To find the probability of drawing a blue marble you need to find how many marbles there are in total.
So you have to add 3 red marbles, 7 blue marbles, and 2 green marbles to get the total.
So 3 + 7 + 2 = 12
There are 12 marbles in total so now you have to find how many blue marbles there are.
There are 7 blue marbles out of 12 marbles.
Now you have to put this as a fraction to see if it can be simplified.
7/12 cant be simplified, so the probability of drawing a blue marble is 7/12.