http://www.ck12.org Chapter 1. An Introduction to Independent Events - Basic
Example 4:You have different pairs of gloves of the following colors: blue, brown, red, white and black. Each
pair is folded together in matching pairs and put away in your closet. You reach into the closet and choose a pair of
gloves. What is the probability that you will choose the blue pair of gloves or a red pair of gloves?
Solution:
P(blue or red) =P(blue∪red) =P(blue)+P(red)=1
5
+
1
5
=
2
5
We have one more set of terms to look at before we finish of our first look at independent and events in probability.
These terms areMUTUALLY INCLUSIVEandMUTUALLY EXCLUSIVE. Mutually exclusive events cannot
occur in a single event or at the same time. For example, a number cannot be both even and odd or you cannot have
picked a single card from a deck of cards that is both a ten and a jack. Mutually inclusive events can occur at the
same time. For example a number can be both less than 5 and even or you can pick a card from a deck of cards that
can be a club and a ten. The addition principle accounts for this “double counting.”
Addition Principle