Q19 - On a certain day, nine

[clarafok]

hello,

i'm not really seeing the gap here, could someone please explain why the answer is A?

thanks in advance!

[bbirdwell]

This is a tricky one. Rather than explain in detail, let me ask you a couple of questions.

Is a plane the same thing as a flight? Does every single flight require a separate plane, necessarily? Or is it possible that one plane flies several flights in a day?

Let me know what you think!

[clarafok]

hmm flights and planes are different, each flight does not require a separate plane, and one plane can definitely fly more than one flight

!!!!!!!!!!!!!!!!!!!!!!!!

ok ok so basically, if more than one or two planes are scheduled for each of the 9 flights, then even if there are mechanical problems, there is still a back up plane to fly the flight right? but if the 9 flights were cancelled anyway, then it must've been due to something other than a mechanical problem!

right??

[slimjimsquinn]

Hi Clara,

It really helps to do the negation on this one. Negating answer choice A) leaves us with the statement "Not more than one or two planes were schedules for the nine cancelled flights." So let's say that there is just 1 plane for all nine cancelled flights. If this 1 planes has a mechanical problem, then all flights must be cancelled (it'd be pretty unsafe to fly with a faulty engine, right?).

Then what does this mean about those 9 cancelled flights? They are ALL the result of the airplane's mechanical failure.

You spotted the assumption! The argument assumes that there is one airplane for every flight. That's sort of inefficient, right? Why would we have airplanes just hanging out at the airport in between flights? Backups are irrelevant for this argument.

Hope that helps!

[Vivi]

HI There, why E is wrong? I kinda think "all" is the problematic word here. Could anyone share a more mechanic solution to adress it? E looks like to provide an alternative cause. In another word, if we change the answer choice to "the airplanes scheduled for the canceled flights are based at the same airport", would it work？ Thanks!

[maryadkins]

HI There, why E is wrong? I kinda think "all" is the problematic word here. Could anyone share a more mechanic solution to adress it? E looks like to provide an alternative cause. In another word, if we change the answer choice to "the airplanes scheduled for the canceled flights are based at the same airport", would it work？ Thanks!

Good question. So if (E) said, "The airplanes scheduled for the canceled flights are based at the same airport," then negating that would be to say, "The airplanes scheduled for the canceled flights are NOT based at the same airport." What would that mean? I suppose that would mean they are different airplanes, since the same plane wouldn't be based at two different airports. Would this help or harm the conclusion? If anything, it would HELP it! Negating your revised version of (E), if anything, makes it more likely that we're talking about different planes.

(E) actually is pretty irrelevant, turns out. It doesn't tell us how many planes there are involved in the canceled flights, and that's what we're talking about. Airport location doesn't really matter since airports can be different sizes.

(A) on the other hand, when negated, reads, "Not more than one or two airplanes were scheduled for the nine flights." This would mean the logic of the argument crumbles, since it relies on there being more than one or two airplanes involved.

As for the others:

(B) isn't an assumption because we were told that it's unlikely Swift would have mechanical problems, so we already know what the likelihood is.

(C) is totally irrelevant.

(D) isn't necessary. So what if they never have before? We're talking about this one instance.