Measure time in Hour Glass | 1 July 2009

shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
You have couple of hour glasses -- A four minute hourglass and A seven minute hour glass. How can you measure 9 Minutes using them.
naimish's Avatar
Banned
To time nine minutes with a four minute and seven minute timer :
Start both timers simultaneously.
When the four minute runs out, start it again.
When the seven minute runs out, begin timing nine minute interval.
Let the remaining minute fall through the four minute and run it twice
more.

7-4=3
4-3=1
1+4+4=9

Simple enough.
naimish's Avatar
Banned
Or another way it is as , turn over both hourglasses at once. When the four-minute hourglass runs out, turn it over. When the seven-minute hourglass runs out, turn it over. When the four-minute timer runs out this time (eight minutes have elapsed), the seven-minute hourglass has been running for one minute. Now turn over the seven minute timer back over. When the timer runs out, nine minutes have elapsed.
nimesh's Avatar, Join Date: Apr 2009
Invasive contributor
naming both the hour glass as 4MHG, 7MHG

0 Min - Both Starts
4 Min - 4MHG runs out, 3 left in 7MHG - Turn 4MHG
7 Min - 7MHG runs out, 1 left in 4MHG - Turn 7MHG
8 Min - 4MHG runs out, 1 reached in 7MHG - Turn both
9 Min - 7MHG runs out (Since on 1 min was left in it), 3 left in 4MHG

I believe this is same as naimish's last answer
SaswatPadhi's Avatar, Join Date: May 2009
~ Б0ЯИ Τ0 С0δЭ ~
I'm late !

Anyway, congrats naimish

naimish and nimesh sound so similar, I hope shabbir won't make a mistake while sending the $1
naimish's Avatar
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Ohh, That means I won ? Cool, Yeye, Now what should be the next step from my side ?
SaswatPadhi's Avatar, Join Date: May 2009
~ Б0ЯИ Τ0 С0δЭ ~
Algorithm :
(1) Wait till shabbir confirms that you've won.
(2) If ( You have entered PayPal Email in your profile )
##Then : Don't worry.
##Else : Enter it !
(3) Accept the $1 from him .
naimish's Avatar
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Yup, It's already updated in my profile

Last edited by naimish; 1Jul2009 at 15:35..
naimish's Avatar
Banned
Quote:
Originally Posted by SaswatPadhi View Post
Algorithm :
(1) Wait till shabbir confirms that you've won.
(2) If ( You have entered PayPal Email in your profile )
##Then : Don't worry.
##Else : Enter it !
(3) Accept the $1 from him .
Thanks for the process buddy Have a good time
shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
So we have a new Winner now.