INDICES

Indices are useful in simplifying large number. You need to understand the concept of statistics.

Objectives:

– To understand the terms: square number, cube number, square and cube root. 
– To learn and use square numbers up to 225.
– To know and be able to use the index laws. 
– To be able to add, subtract, multiply and divide negative numbers.
– To be able to use powers with negative numbers.

Indices Law



Example Question

Permutation and Combination Multiplication rule and Exercise

Permutation and Combination Multiplication Rule

Example:   A NBA Basketball team, Phoenix Sun roster consist of six Guards, four Fowards and three Centers. In how many ways can the coach select a starting line up of two guards, two Fowards and one Center?




Permutation and Combination Exercise

1) In sport house of 24 students, a first and second prize are to be awarded. In how many                      different ways can this be done?

2) In a room of 20, 12 are girls and the rest are boys. A student body of 2 prefects are to be                    elected. How many ways can they be chosen if:

    a. Both prefects elected are girls
    b. Both prefects elected are boys
    c. 1 girl and 1 boy prefects

3) A fan club has 28 members. In how many ways can the president, web-designer and admin            be chosen to form a committee of three?

4) In how many ways can a football team of 11 players be chosen from 30 people?

5) In how many ways can a committee of 7 be chosen from 9 office pairs if:

a. The committee must have 3 men and 4 women
b. No restriction are made
c. The committee are all elected by men

Permutation and Combination

PERMUTATION AND COMBINATION

Permutation   :      Certain number of objects that can be arrange in order from a large number of objects in different number of ways.
                              It is an ordered group/list or an order is important.
Keyword         :      Arrangement

Combination   :     Certain number of objects in a group that can be selected from a large number of objects in different number of ways.
                             It is an un-ordered group/list
Keyword         :     Selection, Election, Choice


FORMULA

Key:-                 n = Number selected     N = Total number     ! = Factorial     

Permutation   :

                                    

Example: How many ways can you arrange these 5 objects?



n = none     N = 5






Combination   :

                                  

Example: How many can you arrange these 5 fruits picking 3 at a time?



n = 3     N = 5





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