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Three boys are ages 4, 6 and 7 respectively. Three girls are [#permalink]
09 Dec 2012, 09:05
72% (02:35) correct
28% (01:48) wrong based on 25 sessions
Three boys are ages 4, 6 and 7 respectively. Three girls are ages 5, 8 and 9, respectively. If two of the boys and two of the girls are randomly selected and the sum of the selected children's ages is z, what is the difference between the probability that z is even and the probability that z is odd?