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Question from rebecca, a student:

how many three digit odd numbers can be formed using the digits 1,2,3,4,5,6 without using any digit more than once?

Hi Rebecca,

An odd number must not have an even last digit, so from our list of digits to use our last one must be either 1, 3, or 5. So we have 3 choices for the last digit of our 3 digit number. If we cannot repeat any digit, how many choices do we have for the middle digit of our 3 digit number? How many digits are left to choose from for the first digit of our 3 digit number?

Just multiply your answers to these questions together, and that is how many 3 digit odd numbers can be formed from 1 - 6 without repetition.

Tyler

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