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Okay Aspiring math people moving on another drill for you

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Place one of the following numbers into the ones digit

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of the number of four Twenty eight while moving the

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other digits so that the four is in the position

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of the thousands digit What one's digit would make the

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number for twenty eight divisible by six and by nine

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Well the problem asked us to shift all digits to

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the left and then tack on one more number to

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the end But which number gets to join the group

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here Well we can't just let any old number join

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the club There are standards to solve this problem We

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need to divide and conquer kind of there's division involved

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anyway at least conquering that's So think of visibility rules

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How does that work How do they work to be

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divisible by six evenly a number must be divisible by

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two and three and even number is divisible by two

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duck and a number is divisible by three If the

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digits add up to a multiple of three what we

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mean by that is like four plus two plus a

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That's fourteen is that divisible by three so much and

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the rule for visibility by nine is similar If the

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digits add up to a multiple of nine like they

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some toe eighteen or twenty seven or thirty six like

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that then it's all good We're also particularly fund of

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this helpful little rule Nine is a multiple of three

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So if a number is divisible by nine then of

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course it must be divisible by three as well In

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other words there's no need to check the rules for

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both three and nine So if you have a niner

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there the three work In short our number needs to

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be divisible by both six and nine In other words

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it needs to be even like in a c t

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And the digits need to add up to a multiple

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of nine Well the on ly answer that satisfies both

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is four So uh that's c right there It gives

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us four thousand two hundred eighty for if we adam

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up for post to hiss six plus aids for eighteen

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plus four there is eighteen eighteen of his wine nine

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and then by definition by three as well So that's

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it That's the answer It's see you'd stick up for

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there in the thousands place and be done with this 00:02:12.578 --> [endTime] thing

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