1. Joined
    08 Dec '03
    Moves
    3140
    27 Jun '04 23:04
    A, B, C and D represent four different digits such that ADDD, AACA, BCDB and BDAC are prime numbers.

    What digits do the letters represent?

    -Ray.
  2. Sheffield
    Joined
    09 Sep '03
    Moves
    7644
    28 Jun '04 14:11
    A, B, C and D represent four different digits such that ADDD, AACA, BCDB and BDAC are prime numbers.

    What digits do the letters represent?
    Each digit is odd since each of the four primes expressed above ends in a different digits A-D.

    No digit is 5, since any number ending in 5 is divisible by 5.

    So the four digits are 1,3,7,9

    We find that A=1, B=3, C=7, D=9
    giving 1999, 1171, 3793 and 3917 as the primes
  3. Joined
    08 Dec '03
    Moves
    3140
    30 Jun '04 02:33
    Originally posted by garethn
    A, B, C and D represent four different digits such that ADDD, AACA, BCDB and BDAC are prime numbers.

    What digits do the letters represent?
    Each digit is odd since each of the four primes expressed above ends in a different digits A-D.

    No digit is 5, since any number ending in 5 is divisible by 5.

    So the four digits are 1,3,7,9

    We find that A=1, B=3, C=7, D=9
    giving 1999, 1171, 3793 and 3917 as the primes
    Looks good to me.

    -Ray.