Did I fall asleep? Or did the the egg timer puzzle never get solved.
ie. You have a 4 minute egg timer and a 7 minute egg timer. How do you accurately time 9 minutes?
I shouldn't have fallen asleep. I really enjoyed it, despite the plot holes I'm reading about.
It was solved, by "Olivia".
shareNot sure if this is exactly how it was phrased, but this works:
A = 4 min timer
B = 7 min timer
Flip both. When A out, 3 mins left on B. Flip A.
When B out, 1 min left on A. Flip B.
When A out, 6 mins left on B. Flip A, put egg in.
When A out, 2 mins left on B, egg has been cooking for 4 mins.
Flip B - 5 mins left so when done will have cooked for 9 mins.
The traditional variant has you cook a perfect 4 minute egg using a 3 minute and a 5 minute timer. After 9 minutes, I doubt it really matters how accurate you have been, your egg is going to be pretty hard!
That's a very convoluted way of doing it waferthinninja. Not quite sure how you arrived at the 5 minutes in the last step there!
Here is the correct solution to this problem as offered by Oliva:
(BTW, if yr timing yr egg put it in now...)
"We start the two clocks at the same time,
the 4 and the 7
When the 4 finishes, four minutes will have passed
We turn it upside down
Three minutes later the sand in 7 is finished
We turn it upside down
When the sand has finished in 4 the second time, eight minutes have passed,
but 7 will have timed one minute
We turn it over
And we've got the nine minutes!"
Simples!
--I do wish Imdb wasn't so riddled by bugs and popups--
Not quite sure how you arrived at the 5 minutes in the last step there!In the 4th line, there where 2min left on B. That means that if you flip B now, it'll time 5 minutes.
j-cameron22 wrote:
but 7 will have timed one minute
xauyala wrote:
No, 6 minutes.
waferthinninja's solution is correct
Here's a graphic representation of Oliva's answer.
http://puzzles.nigelcoldwell.co.uk/images/40graph3.png
From http://puzzles.nigelcoldwell.co.uk/forty.htm
The official answer that she came up with seemed way more convoluted than what occurred to me as it was playing out:
9 = 7 + 1/2(4)
So run the 7-minutes one, then as soon as it finishes, start the 4-minutes one. When the sand in the 4-minutes one is halfway done (ie, the amount of sand left in the top chamber equals the amount that has accumulated in the bottom chamber), 9 minutes is up.