Exercise 3 Page 745

When calculating probability, we are comparing the number of

favorable

o u t c o m e s

to the number of

possible

o u t c o m e s .

To calculate the probability that a randomly chosen cube is not red we will use the Probability Formula.

P = \frac{Favorable Outcomes}{Possible Outcomes}

In the bag, there is a total of

6

red,

4

yellow,

3

blue, and

1

green cubes. The sum of these values is the number of

possible

outcomes .

6 + 4 + 3 + 1 = 14 cubes

Out of these,

4 + 3 + 1 = 8

are not red, which is the number of

favorable

outcomes .

Now we have enough information to calculate

P (not red) .

P = \frac{Favorable Outcomes}{Possible Outcomes}

Substitute values

P (not red) = \frac{8}{1 4}

$\frac{a}{b} = \frac{a / 2}{b / 2}$

P (not red) = \frac{4}{7}

The probability is

\frac{4}{7},

which can also be written as

4 : 7 .