Which one of the following could be a complete and accurate list of lights that are on together?
Gabriela-DiazJune 17, 2020
First Rule
"At least one of any 3 consecutively numbered lights is off"
How do you know that each sequence of three has to have a light off. When I first did this game, I thought that just one of three sequences had to have a light off. For example I thought it was just saying that if 123 has one light off then that meets the rule I did not think that 123, 234, 345, 456, 567, 678 each had to have a light off. Can someone explain how the wording lets you infer that vs what I first thought ? Maybe with explaining with a different example. Thank you !
Replies
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Thanks for the question! Let’s take a look at the wording of the first rule. At least one of any three consecutively numbered lights is off. The key word here is any combined with consecutively. ANY three consecutively numbered lights has to have at least one that is off. That means I can go into the queue and randomly pick any 3 in a row, and there should be one off. And that’s why 123, 234, 345, etc. each have to have at least one light off.
For example, if there’s a line of people, and I say that any three people in a row in the line are going to have at least one woman in that line, that means I can pick out any three people in a row (starting at 2, or 6, or 12) and you should find at least one woman in that group of three.
Hope this helps! Feel free to ask any other questions that you might have.
Gabriela-DiazJune 19, 2020
What if it had just said one of any three lights is off, without saying consecutively numbered ? Or would it have to say one of any eight lights if off if it did not mention consecutive part? Thank you
Gabriela-DiazJuly 8, 2020
Following up. Using your example from above -- "For example, if there’s a line of people, and I say that any three people in a row in the line are going to have at least one woman in that line, that means I can pick out any three people in a row (starting at 2, or 6, or 12) and you should find at least one woman in that group of three."
Would this be treated the same even though the word consecutively is not in it? You said the key to this game was the combo of any with consecutively. But if it had just said any three would we come to the same setup? Thanks. I am taking LSAT soon so a prompt response would be greatly appreciated.
shunheJuly 17, 2020
Hi @Gabriela-Diaz,
Thanks for the question! If the stimulus had just said one of any three lights were off, without saying consecutively numbered, then we could have at most two lights that were on. Because let’s say we had ten lights. That means we could pick any three of them, and at least 2 of them were off. And if there were three lights that were on, we would be able to pick those three. So there would be at most two lights that could be on in that scenario. So we wouldn’t come to the same setup if the word consecutively wasn’t in there; the word consecutively lets us know that it has to be three in a row.
Hope this helps! Feel free to ask any other questions that you might have.
