An actor read aloud and recorded a certain 420-page book on several

Question

An actor read aloud and recorded a certain 420-page book on several audiotapes. Was the average recording time per page less than 90 seconds?

(1) Each tape was at most 40 minutes
(2) The book was recorded on 15 tapes

ID 02444

PrashantPonde · Accepted Answer

Consider T as total time taken to record 420 page book. Average time 90 secs = 1.5 mins.
So question asks is total time T < 420*1.5 i.e.  T<630?

1) Each tape was at most 40 minutes
 INSUFFICIENT : We dont know how many tapes were recorded
2) The book was recorded on 15 tapes
 INSUFFICIENT : We dont know how long each of those 15 takes took for recording

Combining (1) and (2) --We need to prove  T<630 ?
 SUFFICIENT : Tape (out of 15 tapes) spent  at the most 40  mins (i.e.  less than or equal to 40 )
Maximum time that could have spent on recording = 15 * 40 = 600 (which is still less than 630)

Hence choice(C) is the answer.

egmat · Answer

The question asks us... Is Total time spent < 420*3/2 min. => Is Total time spent < 630 min. ? Statement 1 Insufficient, as there is no information given on # of tapes. Statement 2 Insufficient, as there is no information given on lenght of tapes. Combined together Total length of Tapes < 40*15 (600 min.) So Total time spent < 600 min. . Answer C. Hope this is clear now.

-Shalabh Jain

MzJavert · Answer

1) Insufficient by itself. 40 minutes/1.5 minutes = 26.67, so 26.67 or more pages per tape needed to satisfy the question. 
2) Insufficient by itself. 420 pages/15 tapes = 28 pages/tape

1 + 2 28 pages/tape > 26.67 pages/tape

WholeLottaLove · Answer

An actor read aloud and recorded a certain 420-page book on several audiotapes. Was the average recording time per page less than 90 seconds?

Was the total time less than 630 minutes?

(1) Each tape was at most 40 minutes 
INSUFFICIENT

(2) The book was recorded on 15 tapes  
INSUFFICIENT

1+2)

The total amount of minutes on the audiotapes could be at most, 15*40=600 minutes which answers our question "Was the total time less than 630 minutes?"
SUFFICIENT

(C)

zoezhuyan · Answer

dear experts,  chetan2u ,  Bunuel ,  VeritasKarishma ,  GMATBusters ,  nick1816

I picked up E, because I am not sure whether first 14 tapes are recorded 40mins?

please clarify

thanks in advance

nick1816 · Answer

You should check for the extremes in such questions.

For example- Suppose question stem is "Is x<6?" and one of the statement says that x is less than or equal to 3. Even we don't know the exact value of x with the help of the statement, still we can answer the question stem. Same thing is going on in this question.

Combining both statements, average recording time per page  ≤   \frac{15*40}{420 }

We use less than or equal to sign here which means  \frac{600}{420}  minutes is the upper limit of our average time. Since our upper limit is smaller than 600/400 or 1.5 minutes, Answer must be C, not E.

Basshead · Answer

We are told the actor read a 420-page book:

420 * 1.5 minutes = 630 minutes

The question rephrased: Did the actor take less than 630 minutes to record the whole book?

(1) Insufficient. We don't know the time per page.
(2) Insufficient. We don't know the time per page.
(1 & 2) The book was recorded on 15 tapes. Each tape was at most 40 minutes.

40 * 1.5 = 600 minutes. The statements combined tell us that the actor recorded the whole book in at most 600 minutes. 600 < 630. Sufficient.

Hoozan · Answer

GMATBusters   IanStewart

After reading the forum I understood that the Q stem is tekking us that a total of "n" tapes were used to record a book of 420 pages

But, the way the Q stem is written, can't it also mean that each "n" number of tapes has a recording of a book of 420 pages? i.e. each "n" tape had the complete recording of the book?

IanStewart · Answer

Yes, I agree that the question is open to two interpretations (was the recording of a single book divided among the tapes, or was the entire book recorded on each tape?). Unfortunately the answer to the question is different under those two interpretations as well (if you interpret it differently from how they intend, and assume the entire book was recorded on each tape, then Statement 1 is sufficient alone), so this is, I'd say, one of the very rare official questions that is imperfectly designed.

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An actor read aloud and recorded a certain 420-page book on several

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