Results 1 to 3 of 3

Thread: Escalator Question

  1. #1
    Junior Member
    Joined
    May 2009
    Posts
    68

    Escalator Question

    need help with this question.

    Walking down a certain escalator descending at a constant rate, if I take 30 seconds to reach the bottom, I have to walk down 13 consecutive steps. If i take 21 seconds to reach the bottom, I have to walk down 19 consecutive steps. The number of steps showing on this escalator at any one time is:
    a) 32 b) 33 c) 34 d) 35 e) 36
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member Chokfull's Avatar
    Joined
    May 2009
    From
    Neverland
    Posts
    108
    Thanks
    1
    I may be wrong, but I think this is impossible without knowing the speed of the escalator
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Jun 2009
    Posts
    220
    Thanks
    1
    No chokful, although it might not seem like it, there is enough information available.

    Quote Originally Posted by foreverbrokenpromises View Post
    Walking down a certain escalator descending at a constant rate, if I take 30 seconds to reach the bottom, I have to walk down 13 consecutive steps. If i take 21 seconds to reach the bottom, I have to walk down 19 consecutive steps. The number of steps showing on this escalator at any one time is:
    a) 32 b) 33 c) 34 d) 35 e) 36
    Walking down 13 steps gave a time of 30 seconds.
    Walking down 19 steps gave a time of 21 seconds.

    Therefore walking down 6 steps would take a total of $\displaystyle 30-21=9$ seconds, giving us a rate of $\displaystyle \frac{6 ~ \text{steps}}{9 ~ \text{seconds}} = \frac{2}{3}$ steps per second.

    So the total number of steps on the escalator at any given time is given by

    Amount of steps walked down + (Steps per second rate $\displaystyle \times$ Time taken)

    I'll leave it to you to work out the answer, make sure you get the same answer for both of the cases (you will )
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. the escalator problem
    Posted in the Algebra Forum
    Replies: 1
    Last Post: Jan 16th 2011, 08:02 AM
  2. Replies: 2
    Last Post: Oct 14th 2010, 04:07 PM
  3. "Down the Escalator"
    Posted in the Algebra Forum
    Replies: 2
    Last Post: Aug 30th 2010, 01:40 AM
  4. Escalator problem
    Posted in the Calculus Forum
    Replies: 0
    Last Post: May 6th 2010, 01:15 AM
  5. escalator problem
    Posted in the Algebra Forum
    Replies: 1
    Last Post: Jan 17th 2010, 02:03 AM

Search Tags


/mathhelpforum @mathhelpforum