The probability is given by:
P= # of favorable outcomes / total number of outcomes
First, let us find the # favorable number of outcomes, this means the not blue cubes:
7 red cubes
3 green cubes
2 green cubes
Then, 12 not blue cubes
Now, the total number of cubes are:
7 red cubes
3 green cubes
2 green cubes
4 blue cubes
Then, 7+3+2+4 =16 total cubes
Using the equation:
P(selected a cube will not be blue) = 12 / 16 = 3/4
Hence, the correct answer is the third option
