$\"\"$

A bag contains $\"\"$ red marbles, $\"\"$ blue marbles, and $\"\"$ yellow marbles.

Find the probability of blue marbles.

The total number of marbles are $\"\"$ .

The probability of selecting one marble from the total number of marbles are $\"\"$ .

Hence, $\"\"$ .

The probability of selecting one blue marbles is $\"\"$ .

Hence, $\"\"$ .

The probability is $\"\"$ .

$\"\"$ (Substitute $\"\"$ and $\"\"$ )

$\"\"$

The probability of selecting blue marble is $\"\"$ . $\"\"$

The probability of selecting blue marble is $\"\"$ .