Question 140430
In how many ways can three numbers be selected from the set {1,3,4,6,7,8,11} so that the sum of the three numbers is even? In how many ways can three numbers be selected so that their product is odd? 
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There are 7C3 = 7*6*5/1*2*3 = 35 sets of three numbers.
You would have to look at each of those sets and see the sum and/or product
is.
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Cheers,
Stan H.