Question 129555:  Two students, Katie and Carly, are playing a game that uses ten different numbered cards lying face down on a table. The faces of the cards are labeled with one of the numbers from 1 to 10(each card has a different number). If Katie and Carly each turn over a different card, what is the probability that the sum of the two cards is even? 
 Answer by stanbon(75887)      (Show Source): 
You can  put this solution on YOUR website! Two students, Katie and Carly, are playing a game that uses ten different numbered cards lying face down on a table. The faces of the cards are labeled with one of the numbers from 1 to 10(each card has a different number). If Katie and Carly each turn over a different card, what is the probability that the sum of the two cards is even? 
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Make a list of the possible outcomes: 
1+1,1+2,1+3.................1+9 
2+1,1+2,2+3,2+4.............2+9 
3+1,etc 
...... 
...... 
....... 
9+1,1+2,9+3,................9+9 
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Count the number of even results. 
Divide by 100 
That fraction is the probability you are looking for. 
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Cheers, 
Stan H. 
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