Analysis and Approaches for IBDP Maths Ebook 2 | Page 232

Your Practice Set – Analysis and Approaches for IBDP Mathematics
72
Paper 2 Section A – Combinations
Example
From a group of six male students and eight female students, five students are chosen to
form a group.
(a)
(b)
(c)
Determine how many possible groups can be formed.
[2]
Determine how many groups can be formed consisting of three male students and
two female students.
[2]
Determine how many groups can be formed consisting of at least three male
students.
[2]
Solution
(a)
(b)
(c)
The number of possible groups
�14�
� � �
� 5 �
(M1) for valid approach
� 2002
A1
The number of groups
6 8
�
� � � ��
� � �
�
�3� � 2�
M1
� 560
A1
The number of groups
�6� �8� �6� �8� �6� �8�
� � ��� � � � ��� � � � ��� �
�3� � 2� � 4� �1� �5� �0�
M1
� 686
A1
[2]
[2]
[2]
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