| Suggestion from M.theMoon the 09/19/02 : |
You turn up both hourglasses, when the 4min one is empty you put the other one horizontaly = 4min and 3min
You repeat while passing the 3 remaining minutes and while you put the 4mn one horizontaly when the 3min are elasped = 1min and 7min
You start again while passing the minute = 4min and 6min
and once again = 4min and 2min
and (because you're not stingy) a last time = 2min and 7min
So and then, because you aren't bloody stupid, you do flowing one after the other... |
| Very tortuous, difficult to understand and don't answer the question |
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| Suggestion from Azaroth the 09/27/02 : |
It's almost: [7x(7+7+7+7+7)] - [(7+4+7+4+7+4)]= 42-33= 9
accepting, of course, that we can use negative times, but the miracles of modern science... |
| Nonsenses ! |
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| Suggestion from Azaroth the 09/27/02 : |
| I turn up the 7 minutes hourglass, then put horizontaly the 4 minutes one... but I don't think so |
| You are right to don't think so... |
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| Suggestion from Lilou the 09/28/02 : |
|
Firstly you isolate one minute of the 7 minutes hourglass this way:
1. You turn up both hourglasses at the same time
=> When the 4 mn hourglass is empty you have: (eslaped time: 4mn)
- the 4 min hourglass split this way: 0/4
- the 7 min hourglass split this way: 3/4
2. You do flowing the 4 min hourglass and the 7 min hourglass' 3 min at the same time
We turn up the 4 min hourglass
=> You have:
- the 4 min hourglass: 1/3
- the 7 min hourglass: 0/7
3. You do flowing the 7 min hourglass and the remaining minute of the 4 min hourglass
=> You have:
- the 4 min hourglass: 1/7
- the 7 min hourglass: 0/4
Now, you can time 9 min:
you will flown 2 times the 4 minutes hourglass (2*4) + the isolated minute in the 7 min hourglass |
|
| This answer is interesting, but not acceptable, because we can start whan the leader decide |
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| Suggestion from Teva de Tahiti the 09/29/02 : |
He startes both hourglasses at the same time,
when the 4 min hourglass is empty he give the starting signal of the 9 minutes,
at this instant 3 minutes remain in the 7mn hourglass.
When these three minutes are finished
he just have to turn up the 7 minutes hourglass
to have 9 minutes when it's empty. |
This is an answer doubly false, indeed:
- we time 10 mn (3+7=10 and not 9 !!!)
- and we don't start without any preparation |
|
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