Question 136400
How many four-element subsets containing two vowels and two consonants can be formed from the set {a, b, c, d, e, f, g, h, i}?
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Pick two vowels: 3C2 = 3 ways
Pick two consonents: 6C2 = 15 ways
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Total number of ways = 3*15 = 45
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Cheers,
Stan H.