A bag contains 3 red marbles, 5 yellow marbles, and 4 blue marbles. One marble is chosen at random. What is the probability that the chosen marble will be blue?

A) 1/12
B) 1/4
C) 1/3
D) 3/4

I think it is B. 1/4

1/3

Nope.

4/12 = ?

Yes, 1/3

To find the probability of selecting a blue marble, we need to determine the number of favorable outcomes (selecting a blue marble) and the total number of possible outcomes (selecting any marble).

In this case, the number of favorable outcomes is 4, since there are 4 blue marbles in the bag. The total number of possible outcomes is the sum of the red, yellow, and blue marbles, which is 3 + 5 + 4 = 12.

So, the probability of selecting a blue marble is 4/12, which simplifies to 1/3.

Therefore, the correct answer is not B) 1/4, but C) 1/3.