ExplanationFirst figure out how many marbles of each color are in the jar.
For blue:\(\frac{1}{5}\) of 40 is 8, so there are 8 blue marbles and 32 other marbles.
For red: \(\frac{1}{4}\) of 32 is 8, so there are 8 red marbles and 24 marbles that are neither red nor blue. As there are 10 green marbles, there are
14 marbles left that are not green, red, or blue.
Thus, the probability of selecting one of those marbles is \(\frac{14}{40}\).
If you answered \(\frac{26}{40}\), you found the probability that the selected marble will be blue, red, or green.
If you answered \(\frac{12}{40}\), for the red marbles you perhaps found \(\frac{1}{4}\) of 40 (the total marbles) rather than of 32 (the remaining marbles after blue) in the original calculation.
_________________
SandyIf you found this post useful, please let me know by pressing the Kudos ButtonTry our free Online GRE Test