Life is a Test: A Series of Pony Logic Puzzles

by Brony_of_Brody

The Answer 1

It would take 11 ponies to go through all 2000 barrels.

First, you number all 2000 barrels from 1-2000. Then you assign each barrel a unique combination of testers to sample them.

In a simpler scenario with 4 barrels, you only need 2 testers, with each one testing each barrel as follows:

Nopony sups from Barrel 1.

Tester 1 sups from Barrel 2.

Tester 2 sups from Barrel 3.

Testers 1 and 2 sup from Barrel 4.

If they're both fine, Barrel 1 is the infected one. If only Tester 1 gets poisoned, it's Barrel 2 that's infected. If only Tester 2 gets pranked by the plant, it's Barrel 3. And if both testers get hit with Poison Joke, it's Barrel 4.

Working downwards, to test all 2000 barrels, the lowest number of ponies required is 11, for 2048 different combinations of testing. n testers requiring 2ⁿ combinations.

Comments

[Ri2]

Who poisoned the barrels anyway?

[notme]

I come up with it after reading the comments, but I think this is a clearer explanation

you have 2000 barrel, numbered from 0 to 1999,
the nearest higher number which is a power of 2 is 2048 (2^11) so you need eleven ponies
the first barrel is number 00000000000, nopony drink.
second barrel is 00000000001 pony number 1 drink
third barrel 00000000010 pony number 2 drink
fourth barel 00000000011 pony number 1 and 2 drink,
and so on

so if at the end ponies 3, 5, and 9 are affected by poison joke the barrel affected is the number 00100010100 (276)

The only problem is that pony number 1 had to drink from 1000 barrels, in less than 15 minutes. I hope he/she can hold his/her alcohol (and bladder )

[Bed Head]

9202332
Well supposedly you'd only need a drop from each barrel anyway, right?

[CuriousCurse]

An interesting way to reuse testers but now I'm curious if you can get it down further since the full 2028 isn't used. It's only 28 combinations but maybe some interesting combinations or time checks could lower the number further.

Maybe splitting the time sections in half so 7 ponies cycle through twice and then the timing of the effects is used in conjunction with the combination to tell? Hell, if we're talking minute specific affliction (the puzzle stated 45 minutes, not "about 45 minutes"), we could further split it into 6 ponies doing 4 runs over 3 minute intervals (with about 30 seconds of cushioning between each run) or 5 ponies doing 8 1 minute runs with about 45 seconds of cushioning between each run. If dilution isn't an obstacle for the joke, time could be saved by pouring multiple samples into one cup.

Assuming my cheeky modifications are accepted, I may have saved 3 poor ponies from the terrors of cider overdose and joke poisoning.

I might be able to possibly knock off one more with some extreme cider sample mixing and time crunching as technically my 8 run variant has another 7 minutes to spread into and 28 combinations that I need not include from the binary solution.

But pretty much all our solutions kind of ignore the time it would take to set up the logistics of such an operation... I still stand by my personal solution of having it be an ongoing operation that gets a head start now and then is just sending out a regular supply of confirmed non-contaminated ones, though I would alter my method to taking half the barrels and mixing a big mug out of combined little samples to pretty much instantly clear half the barrels for use one way or another.