EPTOn November 21 2012 23:25 DarkPlasmaBall wrote:
While I understand that possible ambiguity/ need to be clever, I'm also pretty sure that based on the context, you really understood that it wasn't a trick question. It means for any given floor, the fact that you're always looking to optimize your answer (not just "get lucky"), and the understanding that you can't risk both rocks breaking without knowing for a fact what the correct floor is. You can't just arbitrarily say, "I choose to pick the two perfect floors to give me the correct answer, meaning the answer's two", because you're incapable of knowing for sure that you'd pick those two ideal floors. You'd need to already know the answers, and then drop the rocks to reconfirm them. However, as the person dropping the rocks, you don't actually know yet what those ideal floors are.
I mean, after all, if you really want to be a dick about it, why not just say, "Well I was super lucky in my individual trial because the answer was "the rock breaks at the first floor" and I dropped my first rock on the first floor and it broke, and therefore I didn't even need the second rock. Answer's one."
It's really missing the point of the brain teaser, because if it hadn't broken, I would have only eliminated one floor in one step, and I'd still have ninety-nine to go... and you simply can't work under the assumption that it will be the first floor, so it's silly to pick floor one to drop the first rock. It will be better for you (probability-wise) to drop the first rock at floor two at step one than at floor one.
While I understand that possible ambiguity/ need to be clever, I'm also pretty sure that based on the context, you really understood that it wasn't a trick question. It means for any given floor, the fact that you're always looking to optimize your answer (not just "get lucky"), and the understanding that you can't risk both rocks breaking without knowing for a fact what the correct floor is. You can't just arbitrarily say, "I choose to pick the two perfect floors to give me the correct answer, meaning the answer's two", because you're incapable of knowing for sure that you'd pick those two ideal floors. You'd need to already know the answers, and then drop the rocks to reconfirm them. However, as the person dropping the rocks, you don't actually know yet what those ideal floors are.
I mean, after all, if you really want to be a dick about it, why not just say, "Well I was super lucky in my individual trial because the answer was "the rock breaks at the first floor" and I dropped my first rock on the first floor and it broke, and therefore I didn't even need the second rock. Answer's one."
It's really missing the point of the brain teaser, because if it hadn't broken, I would have only eliminated one floor in one step, and I'd still have ninety-nine to go... and you simply can't work under the assumption that it will be the first floor, so it's silly to pick floor one to drop the first rock. It will be better for you (probability-wise) to drop the first rock at floor two at step one than at floor one. Yeah, you're right, I was trying to be clever ;o) but my point still stands.
The least number of drops you would need to show the highest floor from which the rock will not drop is still 2, and here I do not assume that I know the floor, I assume the specific case in which a lucky guess was made. And this specific case would yield the result of least dropped rocks: 2.
Your last paragraph I also commented on, but I excluded this as the answer becuase if the rock breaks at the first floor then there is no floor from which the rock survives a drop and the answer is not 1 but null.
