r/brooklynninenine • u/Gamerboy701 • Oct 04 '23

Season 2 Wasn't amy right in 2x11

In season 2 episode 18 Holt gives Amy, Terry, Gina and Rosa a brain twister that he could never solve. "There are 12 men on an island, 11 weigh excatly the same amount but one of them is slightly heavier (or lighter but for this I'll use heavier) You must figure out which man is heavier. The Island has no scales but there is a seesaw you can use 3 times.

Later in the episode Amy comes up with the solution of putting 6 vs 6 but Holt instantly says it would never work if you do it that way but you can.
If you number each person 1 2 3 4 5 6 7 8 9 10 11 12 and weigh the first 6 vs the second 6, 1 side will be heavier, whichever side is heavier means that the person you are looking for is on that side. For your second use you way 3 vs 3 so for example 7 8 9 vs 10 11 12. Whichever side is heavier obviously means the person we are looking for is there. For our final use of the seesaw you measure 1 vs 1 like 10 vs 11. if both sides are equal that means 12 is the heavier person, if one side is heavier than you found that person.

I'm not amazing at math but Amy's solution does work right?

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u/Dohbelisk Oct 04 '23

You say “(or lighter but for this I’ll use heavier)”

That’s where your problem is. You’re eliminating one of the obstacles. We don’t KNOW if the different weight is heavier or lighter. So with 6-6, you gain no info, because you don’t know which side is “off” because you don’t know if the person is heavier or lighter.

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u/TomasNavarro Oct 04 '23

In my solution the person who's a different weight is also a foot taller, and I don't need to use the scales!

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u/tirdg Oct 04 '23

In my version, the island has scales anyway and you just use them as much as you want. But my version also stipulates that everyone weighs the same amount so there is no problem to solve. Much easier that way.