EXAMPLE 3.3.13

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. Since 28 are charming, and 24 of those who are charming are also modest, the number who are charming but not modest must be 28 minus 24 = 4.

2. n(C or M) = n(C) + n(M) minus n(C and M)

= 28 + 26 minus 24

= 30