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Math Help - Riddle help

  1. #1
    jak
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    Riddle help

    I need help with a riddle hoping someone can help


    Mandy is 25 years older than Sandy
    Sandy is 25 yrs younger than Mandy

    Mandy's age is even
    Sandy's age is odd

    Together the sum of their ages is 63 how old is each sister?

    anyone?
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  2. #2
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by jak View Post
    I need help with a riddle hoping someone can help


    Mandy is 25 years older than Sandy
    Sandy is 25 yrs younger than Mandy
    aren't these two statements redundant?

    Mandy's age is even
    Sandy's age is odd

    Together the sum of their ages is 63 how old is each sister?

    anyone?
    this isn't a riddle.

    since Sandy's age is odd, we can write it as: 2n + 1 for n \in \mathbb{N} ...(i used the natural numbers instead of the integers since negative ages make no sense, but whatever).

    since Mandy is 25 yrs older than Sandy, Mandy's age is given by:
    2n + 1 + 25 = 2n + 26

    The sum of their ages is 63, thus we have:

    2n + 1 + 2n + 26 = 63

    now solve for n and you will be able to find their ages
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  3. #3
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    Hello, jak!

    What a silly problem!
    Where did it come from?


    Mandy is 25 years older than Sandy.
    Sandy is 25 yrs younger than Mandy. . . . . well, duh!

    Mandy's age is even. . . . . Not relevant
    Sandy's age is odd. . . . . . Who cares?

    Together the sum of their ages is 63. . . . . Finally, something useful!

    How old is each sister?
    They're sisters? .Boy, that's really important!

    (That's quite an age spread for siblings, isn't it?)

    Let S = Sandy's age.
    Then S + 25 = Mandy's age.

    "The sum of their ages is 63": . S + (S + 25) \:=\:63

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  4. #4
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by Soroban View Post
    Mandy is 25 years older than Sandy.
    Sandy is 25 yrs younger than Mandy. . . . . well, duh!

    Mandy's age is even. . . . . Not relevant
    Sandy's age is odd. . . . . . Who cares?

    Together the sum of their ages is 63. . . . . Finally, something useful!

    How old is each sister?
    They're sisters? .Boy, that's really important!

    (That's quite an age spread for siblings, isn't it?)
    Indeed! I guess the way the question was phrased is supposed to be the riddle, and i fell for it, working too hard. oh well, it happens
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  5. #5
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    sandy is 44 while mandy is 19
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  6. #6
    jak
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    sorry for wasting everyones time thanks for the response. After I posted it, I realized duh as many had suggested....

    anyway thanks for the help
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  7. #7
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    Post hmm

    Quote Originally Posted by jak View Post
    I need help with a riddle hoping someone can help


    Mandy is 25 years older than Sandy
    Sandy is 25 yrs younger than Mandy

    Mandy's age is even
    Sandy's age is odd

    Together the sum of their ages is 63 how old is each sister?

    anyone?
    i think that mandy is 50 and sandy is 25 but i might be wrong
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  8. #8
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by ivananeedshelponmath2 View Post
    i think that mandy is 50 and sandy is 25 but i might be wrong
    50 + 25 = 75. we are told the sum of their ages is 63
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