Question 227267: write a 4 digit number that is divisible by both 6 and 9. Explain how you know without dividing that it is divisible by both 6 and 9.
Found 2 solutions by Theo, solver91311:
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! multiply 60 * 90 to get 3600
this is divisible by 6 and 9 because I created it using factors that contained 6 and 9
3600 / 6 = 600
3600 / 9 = 400
Answer by solver91311(24713)  (Show Source):
You can put this solution on YOUR website!
If the sum of the digits is divisible by 3, then the number is divisible by 3. If the number is even it is divisible by 2. If it is divisible by 2 AND 3, it is divisible by 6. If the sum of the digits is divisible by 9, then the number is divisible by 9 (and also divisible by 3). So you need to make yourself an EVEN 4 digit number where the sum of the digits is divisible by 9.
A number that ends in 2 is even, so let's start with that -- the one's digit is 2. The other three digits must then add up to either 7, 16, or 25.
3222, 1242, 2232, 3132, and lots of others all work.
John
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