Marsha has a bag that contains 4 green marbles, 8 yellow marbles, and 20 red marbles. if she chooses one marble from the bag, what is the probability that the marble is not red?

We know that there are 20 red, 8 yellow, and 4 green marbles.
Together that is a total of 32 marbles.

So, if we subtract the red from the total marbles (32-20), we would get 12 marbles that are not red.

So the probability would be 12/32 marbles that Marsha could pick that would not be red. (Or 1/3)

To take the probability of 1/3 into a percent, we need to convert it into a decimal (which is .333333333(and so on))

You'd multiply .3 by 100 to get .33, and convert it into a decimal which would be 33%

So there is a 33% chance that Martha will grab a yellow or green marble rather than a red one.

(I'm pretty sure this is right, hope it helps)

- Kathryn Irene