Jun Heng's answer to Chew's Junior College 2 H2 Maths Singapore question.
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i)
Number of ways = 3C2×4C3×5C3 = 120
ii)
Number of ways only from L and M = 4C4×5C4+4C3×5C5 = 9
iii)
Number of ways at least 4 from M = 5C4×7C4+5C5×7C3 = 210
iv)
Number of ways without L = 3C3+5C5 = 1
Total number of ways = 12C8 = 495
Number of ways at least 1 from each = 495–1–9 = 485
Number of ways = 3C2×4C3×5C3 = 120
ii)
Number of ways only from L and M = 4C4×5C4+4C3×5C5 = 9
iii)
Number of ways at least 4 from M = 5C4×7C4+5C5×7C3 = 210
iv)
Number of ways without L = 3C3+5C5 = 1
Total number of ways = 12C8 = 495
Number of ways at least 1 from each = 495–1–9 = 485
Date Posted:
1 year ago
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