A man can walk up a moving 'UP' escalator in 30s . the same man can walk down in the moving 'UP' escalator in 90s. assume that his walking speed is same upward and downward . how much time he takes to walk up the escalator when it is not moving.

• as speed x time = distance
  so speed is inversely proportional to time
  speed of goin up/speed of goin down = time to go down/time to go up
  hence speed of goin up = 3 * speed of goin down
  now speed of man+speed of elevator = speed of goin up
  and speed of man - speed of elevator = speed of goin down
  so man's speed is twice the elevator speed
  hence
  2/3=30/x
  whre x is time needed to move up if escalator is stoppd
  so x=45
• 10 years agoHelpfull: Yes(2) No(0)
• Let 'x' be man's speed
  and 'y' be man's speed
  distance travelled each time 'z'
  .
  1st Eq.
  (x+y)z = 30seconds.....(since speed x distance = time)
  .
  .
  2nd Eq.
  (x-y)z = 90 seconds....
  .
  mow add two
  we get,
  2xz = 120 secs
  so, xz = 60 secs
  therefore, it wl take 60 SECONDS for a man to walk up/down on a static escalator with 'x' speed.
• 11 years agoHelpfull: Yes(1) No(2)