Analysis and Approaches for IBDP Maths Ebook 1 | Page 254

Your Practice Set – Analysis and Approaches for IBDP Mathematics
4. A survey of the reading habits of a group of students revealed that 35% read quality
newspapers, 50% read tabloid newspapers and 25% do not read newspapers at all.
(a)
(b)
(c)
Find the percentage of students who read both types of newspapers.
Find the percentage of students who only read tabloid newspapers.
One student is selected at random.
[2]
[2]
(i)
Given that the student selected reads newspapers, find the probability that
he reads tabloid newspapers only.
(ii)
Given that the student selected reads tabloid newspapers, find the
probability that he reads quality newspapers also.
It is also given that 40% of the students wear glasses and 95% of these students read
tabloid newspapers.
[4]
Let G be the event that a student wear glasses and T be the event that a student read
tabloid newspapers.
(d) (i) Explain why G and T are not mutually exclusive.
(ii)
(iii)
Show that G and T are not independent.
Find the percentage of students who do not wear glasses and read tabloid
newspapers.
[7]
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