Tuesday, December 14, 2010

Age Problem 6 Solution

This is the answer to the age algebra word problem that asked, "Bob is one third the age of his father. In 12 years he will be half the age of his father. How old is each now?"


Ok Bob being 1/3 the age of his father is the same thing as saying the father is 3 times as old as him.  It makes it easier to work with.  So let Bob be x and his father be 3x. And in 12 years bob will be half as old as his father.  So we have..


x + 12 =  (3x + 12) / 2

2x + 24 = 3x + 12

x  = 12


So Bob is 12 years old and his father is 3(12) or 36 years old now.  In 12 years Bob will be 12 + 12  or 24 years old and his father will be 36 + 12 or 48 years old which means Bob will be half as old so it checks out.

17 comments:

  1. 48 is the age of the father right?

    ReplyDelete
  2. Christian Eldrich A. De AsisApril 26, 2011 at 10:36 PM

    just think of it and maybe you will get your answer without a solving materials

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  3. 36 ang age ng father!!!!
    shunga

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  4. why the answer is not negative?
    in the reason that you move 24 at the left side?

    ReplyDelete
  5. murag conflict lage 2 ang translation noh!!!!!!!! kung lisulisoun nimo ang imong utok, you wil com up with that solution, pero maka sakit man ug ulo, lantaw nalng sa solution........ he, he, nag rhym lage...

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  6. LET X =age of the father
    1 1
    - X + 12 = - X
    3 2

    1 1
    -X - -X = -12
    3 2

    -1
    -X = -12
    6

    X = (-12)(-6)

    X = 72 AGE OF THE FATHER

    AGE OF BOB = 1
    - (72)
    2

    AGE OF BOB = 36

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  7. how could this be !! explain this to me ! if u transpose that terms into their similar terms !!! the value will be gone !

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  8. oi...wag mo nman laitin..

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  9. i still don't get it! damn! i;m so slow with this :(

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  10. A man and his wife have ages that total 98. He is twice as old as she was when he was as old as she is now. Find current ages.

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  11. b=1/3(f) --->present; in 12yrs: b=1/2(f)+12 -->eq1
    f=f -->present; in 12 yrs:f=f+12

    but also in 12 yrs: b=1/3(f+12)--->eq2

    1/2(f)+12=1/3(f+12)
    1/2(f)-1/3(f)=6-12
    -1/6(f)=-6
    f=36 --->age of Father
    if b=1/3(f)
    b=1/3(36)
    b=12 --->age of Bob

    ReplyDelete
  12. let m for the man and w for the wife, for the problem:
    A man and his wife have ages that total 98. He is twice as old as she was when he was as old as she is now. Find current ages.

    total ages of m+w=98
    and m=2w; while w=w
    let the equation be like this to solve the problem:

    2w+w=98-2
    3w=96
    w=32; the age of wife now
    m=2(32)
    m=64; the age of man

    Note:64 is the twice of the wife's age 32.

    ReplyDelete


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