Results 1 to 3 of 3

Thread: Algebra problem

  1. #1
    Newbie
    Joined
    Nov 2008
    Posts
    4

    Algebra problem

    A computer expert can do a job in 6 hours. His secretary can do the same job in 7hrs. After the expert works on the job foe 2 hours, his secretary takes it and complete the job. How many hrs did it take her to complete the job?

    after 2hrs the experthad completed 1/3 of the job...what do I have to do now?? 1/3 * 1/7
    ..I'm not sure...Could someone help me??? Please.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    12,028
    Thanks
    849
    Hello, lila!

    A computer expert can do a job in 6 hours.
    His secretary can do the same job in 7 hrs.
    After the expert works on the job foe 2 hours,
    his secretary takes over and complete the job.
    How many hrs did it take her to complete the job?

    The secretary can do the job in 7 hours.
    In one hour, she completes $\displaystyle \tfrac{1}{7}$ of the job.
    In $\displaystyle x$ hours, she completes $\displaystyle \tfrac{x}{7}$ of the job.

    The expert has already completed $\displaystyle \tfrac{1}{3}$ of the job.
    The secretary will complete the other $\displaystyle \tfrac{2}{3}$ of the job.

    There is our equation: . $\displaystyle \frac{x}{7} \:=\:\frac{2}{3} \quad\Rightarrow\quad x \:=\:\frac{14}{3}$


    It took her $\displaystyle 4\tfrac{2}{3}$ hours to complete the job.

    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Nov 2008
    Posts
    4
    Thank you Soroban
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Algebra problem
    Posted in the Algebra Forum
    Replies: 8
    Last Post: Apr 22nd 2011, 10:26 AM
  2. pre-algebra problem
    Posted in the Algebra Forum
    Replies: 3
    Last Post: Aug 20th 2009, 05:35 PM
  3. Help! Algebra problem!
    Posted in the Algebra Forum
    Replies: 2
    Last Post: Apr 10th 2008, 11:58 AM
  4. GRE Algebra problem - help
    Posted in the Algebra Forum
    Replies: 5
    Last Post: Mar 7th 2008, 08:55 AM
  5. algebra problem world problem
    Posted in the Algebra Forum
    Replies: 2
    Last Post: May 21st 2007, 03:35 PM

Search Tags


/mathhelpforum @mathhelpforum