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??

**Danger** · Apr26-09, 11:38 PM

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:

Spoiler

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

Originally Posted by junglebeast

jimmy,

your solution takes 6 hours (rounding up).

Round down.

**jimmysnyder** · Apr27-09, 02:15 PM

Originally Posted by davee123

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

Originally Posted by jimmysnyder

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

Originally Posted by jimmysnyder

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

Originally Posted by junglebeast

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

Originally Posted by jimmysnyder

NBAJam100, zero is an even number.

good point... hahaha

**jimmysnyder** · Apr27-09, 03:37 PM

Originally Posted by junglebeast

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.

**LAF** · Apr28-09, 11:26 AM

There must be a value each hour. But maybe a value anytime. So, it´s easy...