Results 1 to 6 of 6

Math Help - Clock problem

  1. #1
    rcs
    rcs is offline
    Senior Member rcs's Avatar
    Joined
    Jul 2010
    From
    iligan city. Philippines
    Posts
    455
    Thanks
    2

    Clock problem

    At what time between 2 and 3 o'clock are the hands of the clock opposite each other?

    please help me on this... kind of dont understand the phrase "the hands of the clock opposite each other" .
    i need your guide on this.


    thanks
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,591
    Thanks
    1445

    Re: Clock problem

    Quote Originally Posted by rcs View Post
    At what time between 2 and 3 o'clock are the hands of the clock opposite each other?

    please help me on this... kind of dont understand the phrase "the hands of the clock opposite each other" .
    i need your guide on this.


    thanks
    It means, at what time in between 2:00 and 3:00 are the hands pointing directly opposite each other (making a straight angle)?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    rcs
    rcs is offline
    Senior Member rcs's Avatar
    Joined
    Jul 2010
    From
    iligan city. Philippines
    Posts
    455
    Thanks
    2

    Re: Clock problem

    Quote Originally Posted by Prove It View Post
    It means, at what time in between 2:00 and 3:00 are the hands pointing directly opposite each other (making a straight angle)?

    According to the book where i got this problem, the answer is 43 and 7/11 min. after 2 oclock. I dont know how they got it because it was not manipulated or shown
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Prove It's Avatar
    Joined
    Aug 2008
    Posts
    11,591
    Thanks
    1445

    Re: Clock problem

    Here's how I would try to do it. In one hour, the hour hand will move from the 2 to the 3, and the minute hand will do a complete rotation from the 12 back to the 12. It should be obvious that the minute hand needs to at least get to the 8 (where it will be opposite the 2) and can not get to the 9 (opposite the 3).

    To get to the 8 takes 40 minutes. 40 minutes is 2/3 of an hour, so the hour hand will be 2/3 of the way between 2 and 3.

    Now think "every minute, the hour hand will move 1/60 of the way between 2 and 3, and the minute hand will move 1/5 of the way between 8 and 9".

    See if you can continue.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    MHF Contributor
    Joined
    Oct 2009
    Posts
    5,540
    Thanks
    780

    Re: Clock problem

    Clock problem-clock.png

    I suggest denoting by x the fraction of the hour that passed after 2 o'clock. Thus, \frac{8}{12}<x<\frac{9}{12}.
    Follow Math Help Forum on Facebook and Google+

  6. #6
    rcs
    rcs is offline
    Senior Member rcs's Avatar
    Joined
    Jul 2010
    From
    iligan city. Philippines
    Posts
    455
    Thanks
    2

    Re: Clock problem

    thanks Sir ProveIt ....
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. The Clock Problem
    Posted in the Differential Geometry Forum
    Replies: 4
    Last Post: February 23rd 2011, 06:15 AM
  2. Clock Problem
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: September 15th 2009, 05:45 PM
  3. clock problem
    Posted in the Algebra Forum
    Replies: 4
    Last Post: August 19th 2009, 10:40 PM
  4. Clock Problem
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: March 4th 2009, 08:12 AM
  5. Clock problem
    Posted in the Algebra Forum
    Replies: 1
    Last Post: November 19th 2008, 11:12 AM

Search Tags


/mathhelpforum @mathhelpforum