0580/22 May/Jun 2026, Question 18: Combined probability
Cambridge IGCSE Mathematics 0580 · Paper 22 (Extended) · Non-calculator · 6 marks
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The question, in short
Ten tiles show 1, 2, 2, 3, 3, 4, 4, 4, 4, 4. Find probabilities for two picks with replacement and three picks without replacement.
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Part (a) · 3 marks
Two tiles are picked with replacement. Find P(both show the same even number).
- 1P(2, 2) = 2/10 × 2/10 = 4/100
- 2P(4, 4) = 5/10 × 5/10 = 25/100
- 3Total = 29/100
Answer29/100
Part (b) · 3 marks
Three tiles are picked without replacement. Find P(their sum is 11).
- 1Sum 11 needs 3, 4, 4
- 2P(3, 4, 4 in that order) = 2/10 × 5/9 × 4/8 = 40/720
- 33 possible orders: 3 × 40/720 = 120/720
- 4= 1/6
Answer1/6
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Also searched as: 0580/22/M/J/26 · 0580_s26_qp_22 · 0580 s26 22 · question 18.
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