Math questions from any Manhattan Prep GMAT Computer Adaptive Test.
funke
 
 

Grilling Steaks Question:

by funke Sun Sep 07, 2008 5:46 pm

I have a question regarding the following DS question. I chose answer choice C for this problem during my CAT Test 4. It was marked incorrect and the answer explanation does not seem clear. The problem comes from Statement (2) Amy's Guests will arrive in half an hour. I understood this as 30min = half an hour. The answer explanation then details that guests could arrive between 25 - 30 min per statement (2). This does not seem very clear to me. Please help!

It takes Amy between 6 and 7 minutes to grill a steak, and she can only grill one steak at a time. She does not need to take breaks between steaks. Can Amy finish grilling all the steaks needed for her party before her guests arrive?

(1) Amy needs to grill four steaks for her party.

(2) Amy's guests will arrive in half an hour.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. Both statements TOGETHER are sufficient, but NEITHER one ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

Answer Explanation:

We're given the information that one steak takes between 6 and 7 minutes to grill.

(1) INSUFFICENT: If Amy needs to grill four steaks, it will take her between (4)(6) = 24 minutes and (4)(7) = 28 minutes, but we don't know when her guests will arrive.

(2) INSUFFICIENT: We don't know how many steaks Amy needs to grill.

(1) AND (2) SUFFICIENT: Amy will take between 24 and 28 minutes to grill the steaks and her guests will arrive in between 25 and 30 minutes, so we cannot answer the question definitively.


The correct answer is E.
RonPurewal
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Joined: Tue Aug 14, 2007 8:23 am
 

by RonPurewal Thu Oct 09, 2008 6:37 am

hmm, yes, i don't see where the 25 minutes comes from, either.

i will bring this problem to the attention of those who tend the cat exams.