EXAMPLE 1.6.13

Among a group of Gators, 26 are modest, 28 are charming, 24 are modest and charming, 864 are not modest and not charming.

How many are...

1. ...charming but not modest?

2. ...modest or charming?

SOLUTION

We will organize the information in a Venn diagram.

1. The diagram shows that there are 4 who are charming but not modest.

2. The diagram shows that the number who are charming or modest (or both) is 4 + 2 + 24 = 30.

We could also get this answer by using the formula:

n(C or M) = n(C) + n(M) - n(C and M)

= 28 + 26 - 24

= 30