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Thread: Harry's Age

  1. #1
    Senior Member harpazo's Avatar
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    Harry's Age

    Jack is twice as old as Harry. Harry is twice as old as Hannah.
    Altogether, they are 63 years old. How old is Harry?

    Jack = 2(2x)

    Harry = 2x

    Hannah = x

    2(2x) + 2x + x = 63

    Is this the correct equation set up?
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  2. #2
    MHF Contributor MarkFL's Avatar
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    Re: Harry's Age

    Yes, that will lead you to the correct result if you solve for 2x, however we are being asked for Harry's age, and so I would set it up as follows:

    Let:

    $\displaystyle H$ = Harry's age, and then:

    $\displaystyle 2H$ = Jack's age and

    $\displaystyle \frac{H}{2}$ = Hannah's age.

    Then, use the information regarding the sum of the ages:

    $\displaystyle 2H+H+\frac{H}{2}=63$

    Solving this equation will directly give us the quantity we are asked to compute.

    Neither approach is necessarily superior to the other though. I simply tend to express things in terms of the quantity we seek, so that we explicitly solve for that variable to answer the question.
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  3. #3
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    Re: Harry's Age

    Oh to be 18 again!!
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  4. #4
    Senior Member harpazo's Avatar
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    Re: Harry's Age

    Quote Originally Posted by Debsta View Post
    Oh to be 18 again!!
    I was 18 years old in 1983. I concur. I would do anything to be 18 again, to go back to the year 1983. As I look in the mirror each day, I see a middle aged man trying to forget the reality that time has indeed rushed by since my teenage years. A sad reality we all must face on this planet---AGING.
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  5. #5
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    Re: Harry's Age

    Quote Originally Posted by harpazo View Post
    I was 18 years old in 1983.
    Quit complaining: I was 42 in 1983!
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  6. #6
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    Re: Harry's Age

    A sad reality we all must face on this planet---AGING.
    Some don't get to face aging. Aging is much better than the alternative.
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  7. #7
    Senior Member harpazo's Avatar
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    Re: Harry's Age

    Quote Originally Posted by Debsta View Post
    Some don't get to face aging. Aging is much better than the alternative.
    I try to be positive but reality is a hard pill to swallow.
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  8. #8
    Senior Member harpazo's Avatar
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    Re: Harry's Age

    Quote Originally Posted by MarkFL View Post
    Yes, that will lead you to the correct result if you solve for 2x, however we are being asked for Harry's age, and so I would set it up as follows:

    Let:

    $\displaystyle H$ = Harry's age, and then:

    $\displaystyle 2H$ = Jack's age and

    $\displaystyle \frac{H}{2}$ = Hannah's age.

    Then, use the information regarding the sum of the ages:

    $\displaystyle 2H+H+\frac{H}{2}=63$

    Solving this equation will directly give us the quantity we are asked to compute.

    Neither approach is necessarily superior to the other though. I simply tend to express things in terms of the quantity we seek, so that we explicitly solve for that variable to answer the question.

    2H + H + H/2 = 63

    3H + H/2 = 63

    2[3H + (H/2)] = 63•2

    6H + H = 126

    7H = 126

    H = 126/7

    H = 18

    Harry is 18 years old.
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