WAEC Mathematics 2019 Objective — Question 34
Question 34 of 145 from the West African Examinations Council (WAEC) Mathematics 2019 Objective paper, with the correct answer and a full explanation.
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34. A box contains 2 white and 3 blue identical balls. If two balls are picked at random from the box, one after the other with replacement, what is the probability that they are of different colours?
- A. 2/3
- B. 3/5
- C. 7/20
- D. 12/25Correct
Explanation
White=2, Blue=3, total=5. P(different colours)=P(1st white,2nd blue)+P(1st blue,2nd white) = (2/5×3/5)+(3/5×2/5) = 6/25+6/25 = 12/25.
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