Question 1075459: Can you help me find a simple solution to this question , Thanks alot in advance
the question is
How many 3-digit numbers can be formed from the digits of the set {2, 3, 4, 5, 6, 7, 8, 9}?, if No repetitions are allowed and the number must be divisible by 3.
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! How many 3-digit numbers can be formed from the digits of the set {2, 3, 4, 5, 6, 7, 8, 9}?, if No repetitions are allowed and the number must be divisible by 3.
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2, 3, 4
2, 3, 7
2, 4, 3
2, 4, 6
2, 4, 9
2, 5, 8
2, 6, 4
2, 6, 7
2, 7, 3
2, 7, 6
2, 7, 9
2, 8, 5
2, 9, 4
2, 9, 7
---
3, 2, 4
3, 2, 7
3, 4, 2
3, 4, 5
3, 4, 8
3, 5, 4
3, 5, 7
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3, 6, 9
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4, 2, 3
4, 2, 6
4, 2, 9
4, 3, 2
4, 3, 5
4, 3, 8
4, 5, 3
4, 5, 6
4, 5, 9
4, 6, 2
4, 6, 5
4, 6, 8
---
etc.
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I don't think there's a "simple formula" for this.
Notice that the sum of the 3 numbers is a multiple of 3 if it's divisible by 3.
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