ORGANIZED COUNTING
(Further Examples)
Example 
Determine the number of possible postal codes.
Sometimes restrictions exist that affect the number of possible choices.
CARDINAL RULE: always deal with restrictions first!!
Example 
A president, secretary, and treasurer are to be chosen
from 2 men and 2 women. No person can hold more
than one office and the treasurer must be a woman.
Determine the number of ways this can be done.
Example 
Determine the number of 3-digit numbers that can be
formed if:
a) repeated digits are allowed;
b) repeated digits are NOT allowed;
c) the numbers must be odd with NO repeated digits;
d) the numbers must be even with NO repeated digits.
Example 
Determine the number of arrangements of the letters of
the word PENCIL if:
a) there are NO restrictions;
b) the letters E and C are adjacent;
c) the letters EC are NOT adjacent.
Example 
Using a standard deck of cards, determine the number
of ways to choose:
a) a black Jack and a diamond, one after the other;
b) a black Jack or a diamond;
c) a black Jack or a spade.
Homework: p.230–231 #13–17, 18ab, 19, 21–24