Luyện tập hoán vị chỉnh hợp tổ hợp (autosaved)

Giáo sinh thực tập: Trần Thị Hằng
Preparation date: 23/10/2018
Title of lesson:
Period 26: EXERCISES ON PERMUTATIONS- ARRANGEMENTSCOMBINATIONS
I.

II.
III.

IV.

GENERAL OBJECTIVES:
1. Knowledge: By the end of the lesson, Students will be able to
- Realize some concepts, definitions, theorems, properties of
numbers ,
and the rule of multiplication.
- Understand some theorems in order to solve some simple
problems.
2. Skills:
- Find number of permutations
- Find number of arrangements
- Find number of combinations
- Apply properties of numbers to real problems.
3. Attitude: love studying, enthusiastic, and active.
METHOD: suggestive approach, problem- solving method, and group
word
PREPARATION:
1. Teacher: Teaching plan for Algebra and Analysis 11, Algebra and
Analysis Textbooks 11.
2. Students: Algebra and Analysis Textbooks 11.
TEACHING PROCESS:

1. Managing class, checking attendance:
Date of teaching

Class

( total) number of
students

11 English 1
2. Checking:
Exercise1: A class has 20 boys and 23 girls. How many ways are
there so that the teacher chooses students joining in outdoor
activity of school if the number of students selected is:
a) 1 student
b) 1 boy and 1 girl.
Solution: a/20+23= 43ways, b/20.23= 460 ways.
3. New lesson:
Activity1 : Exercise 5 ( page 55)

Teacher’s activities
-

-

Divide students into 3 groups,
each group do one part on the
study slip (group 1&3 do part
(a), group 2 do part (b))
Observe the groups
Guide the groups to solve their

problem (if necessary)
Leader of the groups presents
their solutions.

Students’ activities
(a) They number for 3 flower. Each
flower arrangement is a way of
choosing 3 vases and order
them (in the order of flower) so
each way is a 3- arrangement of
5 vases. Therefore, there are =
60 ways of arranging 3 flowers
in 5 vases ( one flower to one
vase) if the flower are different.


Giáo sinh thực tập: Trần Thị Hằng
-

Request members of other
groups to give comment.
Give comment and remark.

(b) Since the flowers look identical,
each way of arranging 3 flowers
in 5 vases (one flower to one
vase) is a way to choose a set
including 3 elements from 5
vases (irrespective of order).
Therefore, there are = 10 ways

of arranging 3 flower in 5 vases(
one flower to one vases) if the
flowers look identical.

Activity 2: Exercise 6 (page 55)

Teacher’s activities

Students’ activities

Request students to read
and solve exercise
- Observe and guide the
students to solve their
problem (if necessary):
+ step 1: A triangle is
defined by 3 non- linear
discriminant points then
each subset (3 points)
of the given set (6
points) defines only 1
triangle.
+step2(conclusion): the
number of triangles can
be formed (from 6 given
points) is number of 3combination of the
given 6 points
- Request a student to
present their solution and
other students to give

comment.
- Make comment and
remark.
Activity 3: Exercise 7 page 55)

A triangle is defined by 3 nonlinear discriminant points then
each subset (3 points) of the
given set (6 points) defines only
1 triangle. Therefore, the
number of triangles can be
formed (from 6 given points) is
= 20 (triangles).

Teacher’s activities

Students’ activities

-

-

Divide students into 3
groups.
Request groups to do
exercise 7
Observe and guide the
groups to solve their
problem (if necessary)
+ step 1: to make a
rectangle, two

consecutive actions
must be performed:
• action 1: select 2
straight lines

To make a rectangle, two
consecutive actions must be
performed:
Action 1: select 2 straight
lines (irrespective of order)
from the given group of 4
parallel lines. The number
of ways to perform the
action is .
Action 2: select 2 straight
lines (irrespective of order)
from the given group of
5lines perpendicular to the


Giáo sinh thực tập: Trần Thị Hằng

-

(irrespective of
order) from the
given group of 4
parallel lines. The
number of ways to
perform the action

is number of 2combination of the
given 4 parallel
lines( ).
• action 2: select 2
straight lines
(irrespective of
order) from the
given group of
5lines
perpendicular to
the four parallel
lines. The number
of ways to perform
the action is
number of 2combination of 5 (
).
+ Step 2: apply
multiplication rule to
find number of
rectangles can be
formed and satisfy
theme.
Leader of the groups
presents their solutions.
Request members of other
groups to give comment.
Give comment and
remark.

four parallel lines. The

number of ways to perform
the action is .
By multiplication rule, there are
.= 6.10= 60 ways or 60

rectangles can be formed.

4. Consolidation:
Request student to recall the main points of the lesson
Exercise1: A dance group has 5 men and 6 women. How many ways
are there to choose any 6 peoples .
solution:
Exercise 2: solve inequation:
P2
Solution: the inequation do not have root because of not
satisfying domain.