Question 885636: Given the digits 0, 1, 3, 5, and 6, how many different four-digit numbers can be made that are divisible by 4 if repetitions are allowed? If repetitions are not allowed?
Answer by Edwin McCravy(20054)   (Show Source):
You can put this solution on YOUR website!
Since any number of hundreds is divisible by 4, in order for
an integer to be divible by 4, only the number formed by
dropping all but the last two digits must be divisible by 4.
Therefore the only choices for the last two digits that can be made
with the digits 0, 1, 3, 5, and 6 are these five: 00,16,36,56, and 60.
So,
we can choose the first digit 4 ways {1,3,5,6}
We can choose the second digit 5 ways {0,1,3,5,6}
We can choose the last two digits 5 ways {00,16,36,56,60}
Answer = 4*5*5 = 100
Edwin
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