• Rajni

MemberJan 8, 2014

Are you fast enough to solve this in 60 seconds?

PUZZLE
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John walk upwards on an escalator, with a speed of 1 step per second. After 50 steps, he was at the end. He turned around and ran downwards with a speed of 5 steps per second. After 125 steps, he returned at the beginning of the escalator.

Can you help John finding out how many steps he needed if the escalator would have stood still?

a)125
b)100
c)200
d)none

stay tuned for more puzzles in future..
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Replies
• MemberJan 8, 2014

125
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• MemberJan 8, 2014

none
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• MemberJan 8, 2014

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• MemberJan 8, 2014

Rajni Jain
Explanation please, I think equation should be.
50/(x-1) = 125/(5-x) where x is speed of elevator.
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• MemberJan 8, 2014

Upwards (along with the escalator), you walk 1 step per second. You need 50 steps, so that takes 50 seconds. This gives the following equation:

L steps - 50 seconds × v steps/second = 50 steps.
Downwards (against the direction of the escalator), you walk 5 steps per second. You need 125 steps, so that takes 25 seconds. This gives the following equation:

L steps + 25 seconds × v steps/second = 125 steps.
From the two equations follows: L = 100, v = 1. When the escalator stands still, you need 100 steps.

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• MemberDec 29, 2015

Can you explain how you arrive at the following conclusion from the two equations 'From the two equations follows: L = 100, v = 1. When the escalator stands still, you need 100 steps.' please.
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• MemberJan 21, 2016

Rajni Jain
PUZZLE
---------
John walk upwards on an escalator, with a speed of 1 step per second. After 50 steps, he was at the end. He turned around and ran downwards with a speed of 5 steps per second. After 125 steps, he returned at the beginning of the escalator.

Can you help John finding out how many steps he needed if the escalator would have stood still?

a)125
b)100
c)200
d)none

stay tuned for more puzzles in future..
100 steps.. the ans is b)
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