Assume that John receives a lower grade in economics than in physics. He must have failed at least one course if whic...

Naz September 25, 2014

Alright, so we are told that John receives a lower grade in Economics than in Physics. We know from the rules that we have a "GP" block, and we also know from the rules that Economics has a higher grade than History.

So we can connect all this to look like the following:

[GP] > E > H

NOTE: it's important to dissect the question stem correctly. Ultimately, we want to see in what scenario must he have failed at least one course.

As you mentioned in your question, if you place G in "B" then H will have a failing grade. But, the question stem asks us "he must have failed at least one course if which one of the following is ALSO TRUE?"

Well, nothing else needs to be true if we start G in "B." Thus, this is our clue as to why we cannot start G in "B;" we need one of the answer choices IN ADDITION to our constraints in the question to force John to have a failing grade. So, we can't just start with a failing grade. Does that clear things up?

Because History has "G," "P," and "E" ahead of it, we know that the best grade that John could have gotten in History is a D. So, History could not fill letter grade A as you mentioned, since there are at least three courses that receive higher grades than it.

Remember, we are looking for the answer choice that TRIGGERS John to fail in at least one thing. So, again, that is why we start off with no failing grades.

We fit our "[GP] > E > H" chain starting from letter grade A and ending in D--so far none failing. As you see in the video explanation (you can access the video explanation by clicking the "play" button on the bottom left-hand side of the screen), answer choices (A) through (D) can be manipulated to not necessarily make John have a failing grade.

However, answer choice (E) forces John to have a failing grade because the best grade History can have is a D and if Russian gets a lower grade than History, then John MUST HAVE failed Russian.

Hope that clears things up! Please let us know if you have any other questions.

Ceci September 21, 2018

Some of the questions we move around where GPRH go but some we keep consistent in A then work out the rest. When do we know if the variables should move around or when to directly place them in the order they're given, when it's never written in the question? Thanks in advance!

Mehran September 21, 2018

@Ceci this would depend on the specific question. Have you watched the video explanations for this game? You can do so by tapping the "play" icon in the top right hand corner.

Brett-Lindsay July 29, 2020

I would have assumed that G could be in second place. If a condition places either R or I ahead of G, then that would cause H to fail.

Why wouldn't we be able to view GPEH as a block? Then anything that came before or after the block would meet the criterion of failing at least one course. In the question, it doesn't specify WHICH course, so there's no ostensible reason it couldn't be H, is there?

Thanks.

Victoria August 4, 2020

Hi @Brett-Lindsay,

Happy to help!

We know that John receives one grade for each of the six courses he took and that the possible grades are A, B, C, D, and E, with E being the only failing grade. This does not necessarily mean that John receives each grade at least once.

The question stem tells us that John received a lower grade in Economics than in Physics. This gives us the following sequence:

G > P > E > H

There is no reason that John could not have failed History; however, we are looking for the answer choice which means that John MUST have failed a course.

We can view GPEH as a "block," but that does not necessarily mean that anything comes before or after it as the stimulus allows for grades to overlap. Without imposing any additional conditions, it is entirely possible that John receives the following grades:

Geology: A
Physics: B
Economics: C
History: D
Italian: A
Russian: B

In this way we have our GPEH block, but John's lowest grade is in History which he did not fail. Therefore, we are looking for the answer choice which ENSURES that John fails a course.

Answer choice (E) does this. Imposing this additional condition makes it so that John must have failed a course because it forces a sequence of grades where they could have otherwise overlapped.

G > P > E > H > R

This means that John must receive an E in Russian.

It is possible that John could have received a B in Geology, meaning that he failed History. However, this is not a sequence that is created by one of the answer choices.

Hope this helps clarify! Please let us know if you have any further questions.