Apps. and Interpretation for IBDP Maths Ebook 1 | Page 261

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Paper 1 – Probability with Tree Diagrams
Example
A bag contains 5 black balls and 2 white balls. Two balls are selected at random without
replacement.
(a)
Complete the following tree diagram.
[3]
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(b)
Find the probability that exactly one of the selected balls is black.
[3]
Solution
(a)
A3
N3
[3]
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