In a bag there are red, green, black, and white marbles. If there are 6 red, 8 green, 4 black, and 12 white and one marble is to be selected at random, what is the probability it will be white

1 answer

To find the probability of selecting a white marble from the bag, we first need to determine the total number of marbles.

The numbers of each color of marble are:

  • Red: 6
  • Green: 8
  • Black: 4
  • White: 12

Now, we can calculate the total number of marbles:

\[ \text{Total marbles} = \text{Red} + \text{Green} + \text{Black} + \text{White} = 6 + 8 + 4 + 12 \]

\[ \text{Total marbles} = 30 \]

Next, we find the number of white marbles, which is 12.

The probability \( P \) of selecting a white marble is given by the ratio of the number of white marbles to the total number of marbles:

\[ P(\text{white}) = \frac{\text{Number of white marbles}}{\text{Total number of marbles}} = \frac{12}{30} \]

To simplify this fraction, we can divide both the numerator and the denominator by 6:

\[ P(\text{white}) = \frac{2}{5} \]

Thus, the probability of selecting a white marble is

\[ \boxed{\frac{2}{5}} \]