3 articles trouvés pour ce sujet.
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Escalator challenge |
2008-04-13 |
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Corey pose la question :
Walking up a broken escalator (escalator not working) takes 75 seconds. Riding up the same escalator (not walking) when it is working takes 45 seconds. How long would it take a person to walk up the escalator when it is working ?
Stephen La Rocque lui répond. |
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More on a man and his wife on an escalator |
2007-02-02 |
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Patrick pose la question :
Hello, I was helping my son with a homework problem and came across a very similar on your site:
http://mathcentral.uregina.ca/QQ/database/QQ.09.01/monty1.html
We are trying to understand the answer shown. There seems to be leap, in the answer that isn't explained or we can't see it. Specifically in the answer it says:
"We know that the woman olny walks 21 steps to reach the top, and thus in the time she walks 7 more steps the escalator also goes up 7 steps. Hence the woman and the escalator are travelling at the same rate."
We understand that she still has 7 steps left, but how is it that you can conclude from that (or other factors) that during those 7 steps the escalator will also travel 7 steps.
Thanks in advance for any help you can offer. Pat
Stephen La Rocque lui répond. |
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A man and his wife walk up a moving escalator |
2002-02-13 |
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Monty pose la question :
A man and his wife walk up a moving escalator. The man walks twice as fast as his wife. When he arrives at the top, he has taken 28 steps. When she arrives at the top, she has taken 21 steps. How many steps are visible in the escalator at any one time.
Peeny Nom and Claude Tardif lui répond. |
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