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Question 221548: How many different pairs of letters from the English alphabet are possible?
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! Ans: 26C2 = (26*25)/(1*2) = 13*25 = 325
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ANOTHER WAY TO DO IT:
Choose the 1st letter: 26 ways
Choose the 2nd letter: 25 ways
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26*25 gives you the total number of pairs you could form
but it includes a/b and b/a which are really just one pair.
So you divide by 2 to get the number of unique pairs.
You get: (26*25)/(2) = 325 unique pairs.
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Cheers,
Stan H.
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