Two Math topics from GMAT_OG_MATH.Zip ??

eeyy

Just downloaded the GMAT_OG_MATH.Zip from these web site and finished it.  There are two questions I thought there are problems.  Looking for any advices.  I pasted the original text in English here, because I found many of the entries(math questions) in this forum is difficult to answer because the translated text is ambiguous.

On page 61 ( printed in the text, actually is page number 38 ):
11. In ΔPQR, if PQ = x + 2, and PR = y, which of the three angles of ΔPRQ has the greatest degree measure?
(1) y = x + 3
(2) x = 2
Explanation:
In any triangle, the largest angle is opposite the longest side. To determine the longest side it suffices to determine whether y > x + 2. Since x + 3 > x + 2, it follows from (1) that y > x + 2. Statement (1) alone is therefore sufficient. From (2) it follows that PQ = 2 and QR = 4. Thus, y can be any value between 2 and 6; it follows that y > x, but it cannot be concluded that y > x + 2. Statement (2) alone is therefore not sufficient. Therefore, statement (1) ALONE is sufficient, but statement (2) alone is not sufficient to answer the question.

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My question is, the question text didn't say QR=x.   what do you say?

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Then on page 65 ( actually page number 42):
4. Yesterday Nan parked her car at a certain parking garage that charges more for the first hour than for each additional hour. If Nan’s total parking charge at the garage yesterday was $3.75, for how many hours of parking was she charged?
(1) Parking charges at the garage are $0.75 for the first hour and $0.50 for each additional hour or fraction of an hour.
(2) If the charge for the first hour had been $1.00, Nan’s total parking charge would have been $4.00.
Explanation:
Statement (1) gives the charge for the first hour and for subsequent hours. From this information, together with the total charge that is given, the number of hours after the first hour can be computed. From statement (2) the charge for the first hour can be determined; however, there is no information about charges after the first hour. Therefore, statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

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I think the answer should be E ( 1+2 together are not enough ) because the rate in (1) for each addtional hours OR FRACTION OF AN HOUR is $0.5   So the total hours could be  a decimal x where 6
Pls advise.  Thx.

eeyy

I suspect the 'GMAT_OG_MATH.zip' is not official, or some texts are missing in this version.   Otherwise I'm going to challenge the ETS directly.
I'm using materials from this web site as the only source to prepare my GMAT test. Should I trust them?  
Thx.