Maths

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Andrew arranged the number 1, 2, 3, ...11, 12 into six pairs so that the sum ofany two numbers in a pair is prime and no two of these primes are equal. find the primes and the pairs

  • Maths -

    I had to solve this by "trial and error" and finally came up with this. There many be other solutions.
    1 + 4 = 5
    2 + 5 = 7
    3 + 8 = 11
    6 + 7 = 13

    9 + 10 = 19
    11 + 12 = 23

    Other prime-number-sum combinations possible would have been 3 and 17, but by forming them I had to use numbers twice or get duplicate sums.

  • Maths -

    (5,8);(3,2);(1,6);(9,10);(4,7);(11,12).

    5+8=13
    3+2=5
    1+6=7
    9+10=19
    4+7=11
    11+12=23

    Hope that helps!!!!! :)

  • Math -

    1+2=3
    3+4=7
    5+8=11
    6+7=13
    9+10=19
    11+12+23

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