Question 697698: How many odd numbers of three digits each can be formed from the digits 2,4,6 and 7 if repetition of digits is permitted.
Answer by Edwin McCravy(20054) (Show Source):
You can put this solution on YOUR website! Odd numbers end in an odd digit. There is just one odd digit, 7,
so we can choose the third digit just 1 way.
we can choose the 1st digit any of 4 ways
we can choose the 2nd digit any of 4 ways
we can choose the 3rd digit just 1 way (as 7),
So the number of ways is 4 = 16 ways
They are:
227, 247, 267, 277,
427, 447, 467, 477,
627, 647, 667, 677,
727, 747, 767, 777.
Edwin
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