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If 2ab is a 3 digit integer, is 2ab divisible by 3?

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If 2ab is a 3 digit integer, is 2ab divisible by 3?

by Max@Math Revolution » Tue Sep 27, 2016 8:02 am
If 2ab is a 3 digit integer, is 2ab divisible by 3?
1) b=3 .
2) 2+a+b is divisible by 9.
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by Max@Math Revolution » Thu Sep 29, 2016 5:35 am
==> In the original condition, the answer is C with two variables (a, b). However, since it is a integer problem that is a key question, if you apply CMT 4(A), in the case of 2) if 2+a+b is divided by 9, 3 digit integer 2ab is divided by 9, and it means it can also be divided by 3, hence yes, and suffi. Therefore, the answer is B.

Answer: B
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