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SaswatPadhi's Avatar, Join Date: May 2009
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Originally Posted by shabbir View Post
So we have a new Winner now.
Yeah, finally !!!!!!
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xpi0t0s's Avatar, Join Date: Aug 2004
Mentor
I know we have a winner but here's another approach...

Using a few trials work out what angle you have to hold the 4 minute one at for it to time exactly 2 minutes. Also work out some angles for other times for when some twit goes "OK smart alec, now do N minutes".
Then time 7 minutes with the 7 minute timer and 2 minutes with the 4 minute timer at the appropriate angle.
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SaswatPadhi's Avatar, Join Date: May 2009
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Quote:
Originally Posted by xpi0t0s View Post
I know we have a winner but here's another approach...

Using a few trials work out what angle you have to hold the 4 minute one at for it to time exactly 2 minutes. <obvious after this, so skipped>
Nice approach. But, I fail to understand how you measure "exactly 2 minutes" !! HOW ?! If you have a watch or something to measure "exactly" two minutes, then why go through all this at all ?? Your 7 mins hourglass can't help you too because 2/7 is not something you can "exactly" measure with naked eyes.
Kindly explain your approach "more" clearly. .... To be specific, please explain how you measure "exactly" 2 mins after a few trials ?!
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xpi0t0s's Avatar, Join Date: Aug 2004
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With a stopwatch, obviously. Which you'll need anyway, because how else would you know that the 7-minute and 4-minute timers are accurate?
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mayjune's Avatar, Join Date: Jun 2009
Invasive contributor
@xpi0t0s
In questions like these you assume that your hourglasses are correct, else by your approach, how do you know your stopwatch is correct too? you assume it to be!
Or consider it that hourglasses were checked with a watch by a 3rd person and given to you...
Hence you cannot have anything else.....
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SaswatPadhi's Avatar, Join Date: May 2009
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Quote:
Originally Posted by xpi0t0s View Post
With a stopwatch, obviously.
Oh really, that was quite cunning.

Quote:
Originally Posted by xpi0t0s View Post
Which you'll need anyway, because how else would you know that the 7-minute and 4-minute timers are accurate?
We know that 'cuz he man who sets the questions defines it for us.

You are not expected to use any kind of tricks here like using a stop watch. Simply use the two hourglasses, compare time as nimesh or naimish pointed out and get a measure of 9 min.
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naimish's Avatar
Banned
Quote:
Originally Posted by shabbir View Post
So we have a new Winner now.
Hi Shabbir, Thank you very much
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shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
Quote:
Originally Posted by naimish View Post
Hi Shabbir, Thank you very much
The pleasure is all mine