$\"\"$

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

Find the probability of red 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 red marble is $\"\"$ .

Hence, $\"\"$ .

The probabity is $\"\"$ .

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

$\"\"$

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

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