How can you distribute 20 lbs of pressure in 5 hours using only odd numbers?

AI Thread Summary
The discussion revolves around a complex engineering puzzle that requires distributing 20 lbs of pressure over 5 hours using only odd, positive integers. Participants debate the feasibility of the task, with some arguing that it is impossible to achieve without using even numbers or zero, which is classified as even. Various proposed solutions are critiqued, with one participant asserting that a solution presented takes more than 5 hours, while another insists it can be done in exactly 5 hours by distributing the pressure at specific times. The conversation touches on the semantics of measuring time and the mathematical implications of the problem, ultimately concluding that the requirement for odd numbers makes the riddle unsolvable, as any combination of five odd numbers cannot sum to an even total like 20.
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Complex Engineering Puzzle!

Distribute 20 lbs of pressure in 5 hours, the numbers Must be Odds and each hour must have a value; you can't use even numbers, nor frations, just positives completes!

wich are the values??
 
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I'm sorry, dude, but that question doesn't really make any sense as presented. Can you express it a bit more accurately?
 


errr wouldn't one of the numbers have to be zero for this to work?? otherwise you would always get at least one even number... right?
 


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.
 


jimmy,

your solution takes 6 hours (rounding up). There is no solution to this question for 5 hours.
 


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
 
Last edited:


junglebeast said:
jimmy,

your solution takes 6 hours (rounding up).
Round down.
 


davee123 said:
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.
 


jimmysnyder said:
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
 
  • #10


jimmysnyder said:
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).
 
  • #11


junglebeast said:
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
 
  • #12


jimmysnyder said:
NBAJam100, zero is an even number.


good point... hahaha
 
  • #13


junglebeast said:
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.
 
  • #14


There must be a value each hour. But maybe a value anytime. So, it´s easy...
 
  • #15


The riddle is impossible, junglebeast is correct.
The riddle states that every hour must have a value,
This doesn't mean each period of time ending in 00 has a value.

That means every 60 minute interval must have a value.
there are only 5 hours in 5 hours (obviously) thus you must have 5 numbers.
Jimmys solution is providing 6. Thus invalid

The reason it is impossible is, if you must chose 5 numbers that add up to 20 it is impossible without chosing an even number.
Any odd number times an odd number creates an even number, always.
 
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