Question 1181318: How many four-digit numbers can be
formed using the digits 1, 2, 3, 4, 5, 6, if the four-digit number is odd?
(Repetition is allowed)
Found 3 solutions by mccravyedwin, Edwin McCravy, ikleyn:
Answer by mccravyedwin(406)   (Show Source):
Answer by Edwin McCravy(20054)  (Show Source):
You can put this solution on YOUR website!
In such problems as these, always make the most restrictive choices first.
Here the most restrictive choice is the last digit, so we choose it first.
Choose the last (or fourth) digit any of 3 ways. (either 2, 4, or 6)
Choose the first digit as any of 6 ways.
Choose the second digit as any of 6 ways.
Choose the third digit as any of 6 ways.
That's (3)(6)(6)(6) = 648 ways.
Edwin
Answer by ikleyn(52778)  (Show Source):
You can put this solution on YOUR website! .
In the solution by Edwin, replace this passage
Choose the last (or fourth) digit any of 3 ways. (either 2, 4, or 6)
by THIS ONE, corrected
Choose the last (or fourth) digit any of 3 ways. (either 1, 3, or 5)
The rest in his solution is correct / (is fine).
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