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Math Help - True or False hurting my head!! MK 2

  1. #1
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    True or False hurting my head!! MK 2

    Thanks for your replies guys.

    In this case:

    True or False:


    If ab Ξ 0 (mod 11) then a Ξ 0 (mod 11) or b Ξ 0 (mod 11). Explain your answer.

    You would agree that the example:

    If a=5.5 and b=2. Clearly ab is congruent to 0 modulo 11, but neither a or b is congruent to 0 modulo 11. Hence this is False.


    This would indicate that it is also false.

    I am not missing anything here am I???
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  2. #2
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    Sorry Forget 5.5 and 2 as mod only deals with whole numbers.

    This then means it may be false.

    factors of 11: 0,11,22,33,44,55,66,77,88,99

    any two numbers that multiply to get any of these that one of them is not a multiple of 11?
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  3. #3
    MHF Contributor alexmahone's Avatar
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    It is true since 11 is prime.
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