There are in total 22 marbles: 4 blue + 5 yellow + 6 red + 2 green + 5 purple = 22 marbles / If there are 4 blue marbles, there are 18 marbles that are not blue: 22 marbles - 4 blue marbles = 18 non-blue marbles
The probability of </span><span>randomly selecting a marble that is not blue is 18 out of 22: 18/22 = 9/11</span><span> </span>