Life is A Test 2: Test Harder (Quite A Bit Harder)

by Brony_of_Brody

More Complications (As If You Weren't Going to Get Any)

Graham's special anti-arthritis meds have now been successfully brewed, and Fluttershy must now move on to a special set of pills that aid in his digestion (he does suffer from rumblings in the night so). However, as is becoming rather disappointingly normal for you, there is, of course, a problem.

The same supplier of Fluttershy's medication has sent along ten bottles of the indigestion pills to her, each one containing the exact same number of pills - attention to detail is everything - but unfortunately, it seems that a rather zealous bunch of environmentalists and slightly mad corporate lawyers broke into their shed and contaminated one of the batches to agitate the symptoms of indigestions right before they mailed them to Flutters. The only way to tell a contaminated pill from another, the note that came with the pill says, is that the intact pills weigh ten grams, while the contaminated ones weigh eleven.

Before you posit that you simply weigh the bottles, as the extra milligrams would surely quickly add up, Fluttershy rather embarrassedly tells you that Discord seemed to take a fancy to the bottle, and made its weight completely indistinguishable from the others - while also just feeding them to unsuspecting Ponyville residents and then blocking all the public toilets. As, you know, the Spirit of Chaos is want to do.

Unfortunately, Zecora's old fashioned pan scales don't go that precise, and so the two of you are forced to use the only other set of electronic scales in Ponyville - at Twilight Sparkle's personal secret lab under the castle, that she denies exists to the public.

Always willing to help a friend out, the princess is of course giving permission to use the scales, but sensing a bit of an opportunity to test you further, she decides to spring a puzzle on you. She takes the ten bottles of meds Fluttershy brought along, measures out ten equal batches, and sets you the challenge. Due to the fact these scales are brand new and she doesn't want your dirty little hooves to damage it too badly, on top of the fact she still hasn't quite forgiven you for the whole cake of evil and death and stuff, she will only allow you one weighing to identify the contaminated batch of pills she has set out for you.

Better solve this one, or else she'll hang this over your head forever. Probably accompanied with some highly immature taunts and raspberries. So, how can you identify the dodgy set of indigestion pills with only one weighing?

Author's Note:

I actually have another weighing one lined up. Won't use it this chapter, but maybe later?

1. Ten batches of medical pills.
2. Contaminated pills weigh 1 mg more than normal pills.
3. A highly sensitive electronic balance.
4. You are only allowed one weighing.

PUZZLE: How can you identify the contaminated batch of pills?

Comments

[Charles Farrow]

The comment section looks like the files on a dangerous SCP or some secret government shit, with all those black lines.

[ScopingLandscape]

Take 1 pills from the first bottle, 2 pills from the second bottle, 3 pills from the third bottle,... you get the idea.
Then set them all on the scale.
If they are all the same weight, that would be 10*(1+2+3+...+10)=450 (mg)
If there is a 1 mg difference, the first bottle is contaminated. If 2 mg, the second. Basically, how much difference in mg will decide which bottle is contaminated.
Why does this work?
Because you take 1 pill from the first bottle, 2 pills from the second bottle and so on and the fact that the contaminated pill weights 1 mg heavier, when you take the pills out like that, you are taking x more grams than if they are not contaminated (aka 450 mg), making the total weight 450+x (mg) with x as the number of pills taken out.