The Counting Principle Sect. 12-1 The Counting Principle

def: An independent event is when the choice of one does not effect the choice of the others. The counting Principle: If an event M can occur in m ways and is followed by independent N that can occur in n ways then the event can occur in ways.

1. How many possible 10 digit phone numbers are possible if they can not begin with a zero?

2. How many nice 4 letter words can be formed using the letters ABCD if each is used exactly once?

How many 2 digit numbers can be formed from 1,2,3,4, and 5 if repetitions are allowed?

Def: A dependent event is when the outcome of one event does effect the outcome of another event

Lets say you want to flip a coin and roll a die all at the same time There are 2 ways you can flip a coin and 6 ways you can roll a die There are ________________ ways you can both flip a coin and roll a die

Tara needs to choose a 4-digit PIN (personal identification number) but she may not use any digit more than once. How many are possible?

How many ways can 12 appointments be arranged in a day? (can’t repeat)

Assignment: Page 715 # 3, 8 ,9, 10, 14, 15, 21, 22, 23, and 26