Results 1 to 3 of 3

Math Help - Problem solving with Quadratics x3

  1. #1
    Junior Member
    Joined
    Feb 2009
    Posts
    63

    Exclamation Problem solving with Quadratics x3

    Jack and Mack both drive 40 km from home to work each day. One day Jack said to mack, "if you drive home at your usual speed, i will average 40 kmph faster than you and arrive home in 20 minutes less time." Find mack's speed.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Apr 2005
    Posts
    15,693
    Thanks
    1466
    Quote Originally Posted by Tessarina View Post
    Jack and Mack both drive 40 km from home to work each day. One day Jack said to mack, "if you drive home at your usual speed, i will average 40 kmph faster than you and arrive home in 20 minutes less time." Find mack's speed.
    Again, V= D/T and T= D/V.

    Letting T be Mack's speed and V Mack's time, then T= 40/V. Driving 40 minues faster and 20 min= 1/3 hour less, T- 1/3= 40/(v+40). T= 1/2+ 40/(V+ 40)= 40/V. Solve for V.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Feb 2009
    Posts
    63
    Quote Originally Posted by HallsofIvy View Post
    Again, V= D/T and T= D/V.

    Letting T be Mack's speed and V Mack's time, then T= 40/V. Driving 40 minues faster and 20 min= 1/3 hour less, T- 1/3= 40/(v+40). T= 1/2+ 40/(V+ 40)= 40/V. Solve for V.
    Could you please help show me the steps of how to solve for x?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Problem solving with Quadratics x4
    Posted in the Algebra Forum
    Replies: 2
    Last Post: February 17th 2010, 10:23 AM
  2. Problem solving with quadratics
    Posted in the Algebra Forum
    Replies: 1
    Last Post: February 15th 2010, 09:45 PM
  3. Problem solving with Quadratics
    Posted in the Math Topics Forum
    Replies: 5
    Last Post: February 13th 2010, 04:19 AM
  4. Quadratics problem solving
    Posted in the Algebra Forum
    Replies: 1
    Last Post: June 6th 2009, 07:55 PM
  5. Problem Solving with Quadratics
    Posted in the Pre-Calculus Forum
    Replies: 7
    Last Post: August 2nd 2007, 08:37 AM

Search Tags


/mathhelpforum @mathhelpforum