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#1 2005-07-05 17:43:41

tt
Member
Registered: 2005-07-03
Posts: 32

two hands of a clock

A man has been waiting for his girlfriend in the park Saturday morning for awhile but the girl didn't arive. He took a look at his watch when started to wait. He left when he saw the minute hand switched places with the hour hand on his watch. How long did he wait (h:mm:ss), knowing that he waited more than 1 hours ?

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#2 2007-03-17 10:32:52

JaneFairfax
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Registered: 2007-02-23
Posts: 6,868

Re: two hands of a clock

One possible answer is 1 hour 50 minutes 600⁄13 seconds (i.e. he waited from 480⁄13 seconds past 11:04 to 300⁄13 seconds past 12:55).

There are other possible answers (e.g. he might have waited from shortly before 10:10 to shortly after 13:50).

Last edited by JaneFairfax (2007-03-17 10:34:12)


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#3 2007-03-17 10:37:10

lightning
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Registered: 2007-02-26
Posts: 2,061

Re: two hands of a clock

i think it was six hours and 30 mins am i right?


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#4 2007-03-17 10:46:24

JaneFairfax
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Registered: 2007-02-23
Posts: 6,868

Re: two hands of a clock

That would be from shortly before 09:15 to shortly after 14:45 (which would be a little over five hours 30 minutes). Very patient man. faint

Last edited by JaneFairfax (2007-03-17 10:48:46)


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#5 2007-03-17 11:31:20

mathsyperson
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Registered: 2005-06-22
Posts: 4,900

Re: two hands of a clock

I'm curious about the shortest waiting time he could have. It's got to be at least an hour, but it can't be just an hour because then the minute hand wouldn't have moved, and so it couldn't switch places with anything. There needs to be a minimum point somewhere.


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#6 2007-03-17 22:03:48

lightning
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Registered: 2007-02-26
Posts: 2,061

Re: two hands of a clock

JaneFairfax wrote:

That would be from shortly before 09:15 to shortly after 14:45 (which would be a little over five hours 30 minutes). Very patient man. faint

he must be in love.......ew


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