In a bag, there are two blue tokens, three red tokens, six yellow tokens, and four green tokens. Stephen will perform random trials of drawing a token and replacing it into the bag. Which of the following is a good prediction for the number of times a red or green token will be drawn in 300 trials?

Well the more trials that you perform the closer you get to theoretical probability which is just:

P (E) = (number of specific Events or outcomes) / (total number of possible outcomes)

P (Red) = (number of red tokens) / (total number of tokens)

P (R) = 3/15

P (G) = 4/15

So the probability of red OR green is:

P (RorG) = 3/15+4/15=7/15

So in three hundred trials you should expect to draw red or green:

300 (7/15) = 140 times.