Apps. and Interpretation for IBDP Maths Ebook 1 | Page 271

Exercise 76
1. Consider the events A and B . It is given that P( A) � 0.4 , P( B) � 0.65 and
P( A�B) � 1.
(a) Find P( A� B)
.
(b) Find P( A�� B)
.
Consider another event C . It is also given that P( C) � 0.7 and P( AC� | ) 0.78 .
[2]
[2]
(c) (i) Find P( A� C)
.
(ii) Find P( A�� C)
.
(iii) Find P( A� ) .
18
(iv) Hence, find P( C| A� ) .
[9]
2. In a school, students are required to take at least one subject from art and technology. It is
known that 55 % of the students take art, and 70 % take technology.
(a) Find the percentage of students who take both art and technology.
[2]
(b) Find the percentage of students who take one subject only.
[2]
At this school, 63 % of the students are male, and 72 % of the male take art. A student is
chosen at random.
(c) (i) Find the probability that the student chosen is a male art student.
(ii)
(iii)
(iv)
Find the probability that the student chosen is a female art student.
Find the probability that a female student is chosen.
Given that a female student is chosen, find the probability that she takes
art.
[9]
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