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-   -   A is 4 yrs older than B, in 7 yrs the sum of age will be 70 how old are they? (https://www.askmehelpdesk.com/showthread.php?t=443312)

  • Feb 4, 2010, 08:12 PM
    zhazen
    A is 4 yrs older than B, in 7 yrs the sum of age will be 70 how old are they?
    Math problem A is 4 yrs older than B in 7 years the sum of their ages will be 70. How old are they now?
  • Feb 5, 2010, 12:17 AM
    amy99roo

    Sounds like algebra
    Use two equations and substitute the variables into the other:

    Equation 1: B+4= A
    Equation 2: A+B+7= 70

    Now substitute equation 1 into equation 2:

    (B+4)+B+7= 70

    Combine like terms and solve for B:

    2B+11= 70
    2B= 70-11
    2B= 59
    B= 59/2
    B= 29.5

    Plug B into equation 1 and solve for A:

    29.5+4= A
    A= 33.5

    Check with equation 2:
    A+B+7=70
    33.5+29.5+7= 70
  • Feb 5, 2010, 11:55 AM
    Unknown008

    A is older than B.

    This means that the age of A is greater than that of B.

    A - 4 = B

    (If you removed 4 years from A, both would be of the same age)

    Then, 7 years later, A would be (A+7) and B would be (B+7), making a total of

    (A+7) + (B+7) = 70

    You can simplify to : A + B + 14 = 70, then to A + B = 56.

    From
    A + B = 56 and
    A - 4 = B, you can substitute B:

    A + (A - 4) = 56
    2A - 4 = 56
    2A = 60
    A = 30

    Then, (30 - 4) = B
    So, B = 26.

    Check, today, A is 30 and B is 26. So, A is indeed 4 years older than B.
    In seven year's time, A will be 37 and B will be 33. Sum is 70!

    Answers:
    A = 30
    B = 26
  • Feb 5, 2010, 12:12 PM
    amy99roo

    So much for that engineering degree! Ha ha!
  • Feb 5, 2010, 12:15 PM
    Unknown008

    Don't worry, now that you found your mistake, I doubt you'll repeat a similar one again :)
  • Feb 5, 2010, 12:16 PM
    MsMewiththat

    Lucky kid just got their homework done! LOL
  • Feb 5, 2010, 12:17 PM
    amy99roo

    Somehow I doubt it! F in math for me! Computers calculators and reports make you dumber!
  • Feb 5, 2010, 12:22 PM
    Unknown008

    How about asking the OP another question and make him/her answer and post his/her answer? ;)

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