there is a bag filled with 3 blue, 4 red and 5 green marbles. a marble is taken at random. what is the probability of exactly 1 red?

4 / 12 or 1/3

Step-by-step explanation:

The total is 3 blue, 4 red and 5 green marbles which is 12 marbles altogether.

There is exactly 4 marbles out of the 12 marbles that are red so the probability of choosing a red is 4 / 12 or 1/3

P 1 red) = 1/3

Step-by-step explanation:

We have 12 marbles (3+4+5)

P (red) = red marbles / total marbles

= 4/12 = 1/3