View Full Version : Complex Engineering Puzzle!!!
reinaldo
Apr26-09, 10:23 PM
Distribute 20 lbs of pressure in 5 hours, the numbers Must be Odds and each hour must have a value; you cant use even numbers, nor frations, just positives completes!!
wich are the values??
I'm sorry, dude, but that question doesn't really make any sense as presented. Can you express it a bit more accurately?
NBAJam100
Apr27-09, 12:05 AM
errr wouldnt one of the numbers have to be zero for this to work?? otherwise you would always get at least one even number... right?
jimmysnyder
Apr27-09, 04:26 AM
There is not one single answer, but here is one possible answer:
midnight - 1
1 0'clock - 1
2 0'clock - 1
3 0'clock - 1
4 0'clock - 1
5 0'clock - 15
That's an odd number at each hour, and 20 in 5 hours.
NBAJam100, zero is an even number.
junglebeast
Apr27-09, 12:15 PM
jimmy,
your solution takes 6 hours (rounding up). There is no solution to this question for 5 hours.
davee123
Apr27-09, 01:22 PM
You could wait until daylight savings to switch, then 5 hours magically becomes 4 or 6, and you're golden.
Technically, Jimmy's takes 5 hours, not 6 hours, it's just that it doesn't take up a full hour. So he's assuming (for example):
12:30:00 - 1
1:30:00 - 1
2:30:00 - 1
3:30:00 - 1
4:30:00 - 1
5:29:59 - 15
Hence, the "hour" of midnight has 1 in it, and the "hour" of 1 has 1 in it, etc. At least, that's my understanding of his answer.
DaveE
jimmysnyder
Apr27-09, 02:11 PM
jimmy,
your solution takes 6 hours (rounding up).
Round down.
jimmysnyder
Apr27-09, 02:15 PM
You could wait until daylight savings to switch, then 5 hours magically becomes 4 or 6, and you're golden.
Technically, Jimmy's takes 5 hours, not 6 hours, it's just that it doesn't take up a full hour. So he's assuming (for example):
12:30:00 - 1
1:30:00 - 1
2:30:00 - 1
3:30:00 - 1
4:30:00 - 1
5:29:59 - 15
Hence, the "hour" of midnight has 1 in it, and the "hour" of 1 has 1 in it, etc. At least, that's my understanding of his answer.
DaveE
Your solution takes 4 hours, 59 minutes and 59 seconds. Mine takes 5 hours.
davee123
Apr27-09, 02:37 PM
Your solution takes 4 hours, 59 minutes and 59 seconds. Mine takes 5 hours.
That gets into the discussion of whether or not you can measure an infinitesemal unit of time, of course-- I was just going by the "normal" measure of time which is to say that since the majority of the full second at 5:30:00 lies AFTER the 5 hour mark, you usually measure the hour to the tail end of the preceeding second. Sort of like why 12:00:00 is PM instead of AM or just "M". The time between the instant it hits 12:00:00 and the instant it hits 12:00:01 is for all intents and purposes 100% (immeasurably smaller) in PM rather than "M", and hence is considered "PM".
But that's just semantics.
DaveE
junglebeast
Apr27-09, 02:38 PM
Round down.
The problem specifies that you must do it in 5 hours. Your solution is over the range of [0,5] which takes more than 5 hours, and is therefore an invalid solution. You need a solution that is in the range (0,5) or (0,5] or [0,5).
davee123
Apr27-09, 02:47 PM
The problem specifies that you must do it in 5 hours. Your solution is over the range of [0,5] which takes more than 5 hours, and is therefore an invalid solution. You need a solution that is in the range (0,5) or (0,5] or [0,5).
It's not actually taking more than 5 hours-- it's taking *exactly* 5 hours (rounding up or down will yield the same result), and is assuming something that's physically impossible, but mathematically correct. If you imagine a square aligned in the XY plane, for instance, with 1 corner at the origin, and side lengths of 5, the corner on the Y axis isn't at 0,4.9999...., it's at 0,5. So he's basically assuming you can distribute it instantaneously.
DaveE
NBAJam100
Apr27-09, 02:47 PM
NBAJam100, zero is an even number.
good point... hahaha
jimmysnyder
Apr27-09, 03:37 PM
The problem specifies that you must do it in 5 hours. Your solution is over the range of [0,5] which takes more than 5 hours, and is therefore an invalid solution. You need a solution that is in the range (0,5) or (0,5] or [0,5).
The length of (0,5), (0,5], [0,5) and [0,5] were all 5 when I went to school.
There must be a value each hour. But maybe a value anytime. So, itīs easy...
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