Math questions from any Manhattan Prep GMAT Computer Adaptive Test.
yyasin1061
 
 

A certain musical scale has 13 notes, each having

by yyasin1061 Fri Mar 30, 2007 3:58 pm

A certain musical scale has 13 notes, each having a different frequency, measured in cycles per second. In the scale, the notes are ordered by increasing frequency, and the highest frequency is twice the lowest. For each of the 12 lower frequencies, the ratio of a frequency to the next higher frequency is a fixed constant. If the lowest frequency is 440 cycles per second, then the frequency of the 7th note in the scale is how many cycles per second?

is A an answer to this problem?


thanks
Kate
ayang
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Answer to #434 (10th)

by ayang Fri Mar 30, 2007 5:41 pm

Yes Kate, you'll be happy to know that the answer to that question is indeed (A). Nice job! :D

Let us know if there's anything else that we can provide. Best, - Andrew
Deepak_J_Shah
 
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Re: A certain musical scale has 13 notes, each having

by Deepak_J_Shah Mon Feb 23, 2009 10:33 am

Shouldnt the answer be (D)?
(How come (A)?)

What am i getting wrong? PLEASE EXPLAIN

440->880; mid-point (which is also the 7th node) would be (880+440)/2=660.

Ans Y Y 440 * Y X*Y =
(A) SQRT(2) 1.41421 440* 1.41421 622.254
(B) SQRTof 2 to the 7th 11.3137 440 * 11.3137 4978.03
(C) SQRTof 2 to the power of 12th 64 440 * 64 28160
(D) 2 to the power of 7/12 1.49831 440 * 1.49831 659.255
(E) 2 to the power of 12/7 3.28134 440 * 3.28134 1443.79

Please respond at Deepak_J_Shah@yahoo.com
Thank you
esledge
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Re: A certain musical scale has 13 notes, each having

by esledge Mon Mar 16, 2009 3:55 pm

Sorry Deepak, this problem is from the OG, which is currently on our forum banned sources list (because it is copyrighted material sold by GMAC). The prior discussion occured before that policy was enacted. I see that you are a current class student, so you may want to discuss this one in your office hours. Again, our apologies.
Emily Sledge
Instructor
ManhattanGMAT