Question

A bag has 12 red marbles and 6 green marbles. Half of the green marbles are made of plastic. A marble is selected at random from the bag. What is the probability that it is a green, plastic marble? Write your answer as a fraction in simplest form.

Answer 1

1/6 is the probability of it being a green plastic marble.

Explanation:

Note that there are 18 marbles in all (12 + 6 = 18).

Half of the green marbles (6) are made of plastic: 6/2 = 3

From the information above, we see that 3 green marbles are made of plastic. There are 18 marbles in all.

Divide, and simiplify.

(3/18)/(3/3) = 1/6

1/6 is the probability of it being a green plastic marble.

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