FUNDAMENTAL COUNTING PRINCIPLES
Ifthe first operation can be performed in
n₁ ways and the second operation in n₂
ways, then the entire experiment can be
performed in n₁ x n₂ ways.
3.
EXAMPLE #1
In theexperiment of tossing a coin and
rolling a die, how many elements can be
made? n (Coin) = 2
₁
n (Die) = 6
₂
2 x 6 = 12 elements
EXAMPLE #2
How manyelements are there in the
experiment of choosing a color from red,
blue and yellow, and tossing a coin?
n1 (Coin) = 2
n2 (Color) = 3
2 x 3 = 6 elements
6.
Red (R) Blue(B) Yellow (Y)
Head (H) HR HB HY
Tail (T) TR TB TY
There are 6 elements
7.
EXAMPLE #3
Suppose youcan have pancake, cereal, or sandwich
for your breakfast and juice or milk for your drink.
How many choices do you have in all for your
breakfast?
n1 (Food) = 3
n2 (Drinks) = 2
2 x 3 = 6 choices
8.
EXAMPLE #4
Daniel isplanning to purchase a photo album. It
comes in three sizes, small, medium, and large; and
the cover comes in hard or soft bound. The pages can
be glossy or silk, and the print can be colored or plain
black and white. How many choices does he have for
the photo album?
9.
n1 (Sizes) =3 n3
(Pages) = 2
n2 (Cover) = 2 n4 (Print) =
2
3 x 2 x 2 x 2 = 24 Choices
PERMUTATION
An arrangement ofa given set.
In the arrangement of n objects there are n operations
involved. The first operation involves choosing an item
for the first position; the second operation, choosing an
item for the second position and so until the nth
operation.
EXAMPLE #2
In howmany ways can the letters of the
word “FAITH” be arrange?
n = 5
n! = 5!
5! = 5 x 4 x 3 x 2 x 1 = 120 ways
17.
EXAMPLE #3
Alex, Alvin,Alyssa, Alfred, Alan, and Aljon are to
occupy the front seats of the auditorium. In how
many ways can they arrange their seats?
n = 6
n! = 6!
6! = 6 x 5 x 4 x 3 x 2 x 1 = 720 ways
EXAMPLE #1
A familywith 6 members sit in a round table
for dinner. How many ways can the member of
the family be seated?
n = 6
(n – 1)! = (6 - 1)!
5! = 5 x 4 x 3 x 2 x 1 = 120 ways
20.
EXAMPLE #2
In howmany ways can 7 appetizers be
arranged on a circular tray?
n = 7
(n – 1)! = (7 - 1)!
6! = 6 x 5 x 4 x 3 x 2 x 1 = 720 ways
EXAMPLE #1
How manytwo digits number can you make
from numbers 1, 2, 3, and 4?
n = 4
r = 2
4P2 = = = 12 ways
27.
EXAMPLE #2
In howmany ways can you arrange 6 books in
a bookshelf, if the capacity of the bookshelf is
only 4 books?
n = 6
r = 4
6P4 = =
= 360 ways
28.
EXAMPLE #3
Brian, Brenda,Brix, Brandon, and Brylle are to
sit in the front seat of the auditorium, if there
are only 2 seats left, how many ways can they
choose and arrange 2 persons to sit in the
front seat of the auditorium?
EXAMPLE #4
There are7 members in a group. Three of
them are to be appointed as president, vice
president, and secretary. How many ways can
one choose the president, the vice president,
and the secretary from the group?
PROBLEM #1
In howmany ways can the letters
of the word “COURAGE” be
arranged?
34.
PROBLEM #2
A familyconsist of 9 members, In
how many ways can they arrange
their seat in a round table?
35.
PROBLEM #2
A familyconsist of 9 members, In
how many ways can they arrange
their seat in a round table?
36.
PROBLEM #3
Suppose youhave 7 pens, 3 of them
are color blue, 2 are color red and 2
are color black, in how many ways can
you arrange the pens in a pen case?
37.
PROBLEM #4
How manyarrangement can you
make if there are 8 persons to be
seated but there are only 5 seats
available?
COMBINATION
A way ofselecting r objects out of n objects where
arrangement is not important.
The set of the different combinations formed from n
objects taken r at a time is a subset of the set of
permutation.
PROBLEM #2
In howmany ways can 9 students
out of 14 students be chosen to be
a part of the school glee club?
51.
PROBLEM #3
In theclass of 30 students, 4 of them are to
be announced as the class valedictorian,
salutatorian, first honor, and second honor. If
all of them are qualified to the said titles, in
how many ways can 4 students be selected?
EXAMPLE #1
A mathteacher is thinking of forming a
committee that will oversee the celebration. He
would like to select two boys and three girls
from his class of 12 boys and 14 girls. How
many combinations of two boys and 3 girls are
possible?
54.
EXAMPLE #2
Three coloredpaper strips are drawn at random from a container
containing three red and five yellow strips.
A. How many combinations of three colored paper strips can be
drawn?
B. How many combinations of three red paper strips can be drawn?
C. How many combination of two yellow paper strips and a red paper
strips can be drawn.