Apps. and Interpretation for IBDP Maths Ebook 1 | Page 256

Your Practice Set – Applications and Interpretation for IBDP Mathematics
(b)
Exercise 71
The required probability
� 6 � 5 � 7 � 3 �� 6 � 5 � 7 � 3�1�
� � �� �
� 25 �� 25 �1
�
� 21 �� 20 �
� � �� �
� 25 �� 24 �
7
�
10
A1 N3
(A2) for correct formula
[3]
1. There are 20 students in a classroom, and each student studies only one extra language.
The table below gives their choices of languages and gender.
Spanish French German
Male 3 2 4
Female 3 3 5
(a)
One student is selected at random.
(i)
Calculate the probability that the student is a male or studies French.
(b)
(ii) Given that the student selected is female, calculate the probability that the
student does not study Spanish.
[4]
Two students are selected at random. Calculate the probability that neither student
studies German.
[3]
2. There are 50 people in a house, and each person wears a uniform of different colours. The
table below gives their colours of uniforms and gender.
Red Yellow Green Blue
Male 5 2 10 5
Female 10 3 5 10
(a)
One person is selected at random.
(i)
(ii)
Calculate the probability that the person is a female or wears a yellow
uniform.
Given that the person selected is female, calculate the probability that the
person does not wear a red uniform.
[4]
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