If the only message Pasquale left is the fifth message, then which one of the following could be true?

shunhe January 7, 2020

Hi @SorooshKosha,

The deduction that H can't be first because P is not in 6th is certainly true. This is just the contrapositive of the third rule. If H is in the first spot for (B), then that just proves (B) can't be possible. But here's another way of looking at it.

Let's say that T left exactly two messages, and we know that P is fifth. If T left exactly two messages, everyone else who left a message left exactly one message based on rule 1. We know that there are 6 total messages and 6 total people, with one of them answering twice; that means that 5 people are going to leave messages, and 1 of them won't leave any messages.

Let's say that F leaves a message. If F leaves a message, then P has to be in front of all of T's messages based on one of the rules. But P is in the fifth spot, and T leaves two messages, so this isn't possible since there's only 6 spots total. So it's not possible that F leaves a message.

So in this case, F doesn't leave a message. That means that G, H, L, P, and T leave messages because we deduced that 5 people leave messages. But we're told that if G leaves a message, F also leaves a message (rule 4). Thus, it's not possible that F doesn't leave a message. If It's impossible for F to leave a message and for F to not leave a message, we know that our initial assumption was wrong, and so (B) is wrong. Hope this helps!

Jamie-Porto July 13, 2020

I feel this video needs to be re-done, having it throw the H in the first spot does not make any sense when it obviously shows h cannot be in the fist spot. I am a visual learner and this has completely thrown me off.

Kai1 July 18, 2023

I agree with Jamie. The individual in the video eliminated an answer by using an incorrect application of the rules. The video needs to be re-done for clarity.