Answer:
~0.143
Explanation:
So, in total there are 15 marbles, and only 6 of them are red. So the first draw will have a chance of being red. Since you didn't mention placing it back, the next draw will have a chance of being red. It's , because you just took a red one out of the bag (leaving 5 left) and the total was lessened by one. To get the answer, you'd multiply both numbers together.
6/15 x 5/14 = 1/7 or (roughly) 0.143