Analysis and Approaches for IBDP Maths Ebook 1 | Page 246

Your Practice Set – Analysis and Approaches for IBDP Mathematics
(b)
The required probability
5 2 2 5
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(M1)(A1) for correct formula
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10
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21
[3]
Exercise 79
1. A bag contains 3 red balls and 5 blue balls. Two balls are selected at random without
replacement.
(a)
Complete the following tree diagram.
[3]
(b)
Find the probability that exactly one of the selected balls is blue.
[3]
2. A bag contains 4 yellow marbles and 5 purple marbles. Two marbles are selected at
random without replacement.
(a)
Complete the following tree diagram.
[3]
(b)
Find the probability that at least one of the selected marbles is purple.
[3]
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