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Math Help - Age Problem

  1. #1
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    Age Problem

    The sums of the ages of grandpa, dad and my brother is 85. Three years ago, grandpa was twice as old as dad. Four years from now, dad will be fours times as old as my brother. How old are they now?

    Thanks.
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  2. #2
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    Hi,

    G = grandpa's age
    D = dad's age
    B = brother's age

    G + D + B = 85
    G - 3 = 2*(D - 3)
    D + 4 = 4*(B + 4)

    Three equations with three variables. Can you do the next step?
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  3. #3
    A riddle wrapped in an enigma
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    Quote Originally Posted by reiward View Post
    The sums of the ages of grandpa, dad and my brother is 85. Three years ago, grandpa was twice as old as dad. Four years from now, dad will be fours times as old as my brother. How old are they now?

    Thanks.
    Hi reiward,

    Let's do it with one equation....for fun.

    Let x = dad's age

    2(x-3)= grandpa's age -3
    2(x-3)+3 = grandpa's age

    x + 4 = 4(brother's age +4)
    x + 4 = 4 (brother's age) +16
    (x - 12)/4 = brother's age

    Now, add 'em up.

    x + 2(x-3)+3+(x-12)/4 = 85

    x + 2x-6+3 + (x-12)/4 = 85

    4x + 8x - 12 + x - 12 = 340

    13x = 364

    x = 28 (Dad's age)

    2(x-3)+3 = 2(28-3)+3 = 2(25)+3 = 53 (Grandpa's age)

    (x-12)/4 = (28-12)/4 = 16/4 = 4 (Brother's age)
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