A bag contains 6 orange 7 green and 8 yellow marbles Find the probability of picking 3 yellow marbles if each marble is returned to the bag before the next marble is picked?

Well, honey, if you're reaching into that bag three times and each time you're pulling out a yellow marble and then putting it back in, the probability of picking a yellow marble each time is 8/21. Multiply that by itself three times because you're picking three marbles, and you get a probability of 512/9261. So, good luck with those yellow marbles, darlin'!