cheese from each Deli

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cheese from each Deli

by kamu » Wed Mar 11, 2009 1:15 pm
Julian bought 6 kilograms of cheese from each Deli A and Deli B. At which deli did he spend more money on
cheese?
(1) The ratio of American to Provolone to Swiss purchased at Deli B was 2 : 7 : 2
(2) The ratio of American to Provolone to Swiss purchased at Deli A was 6 : 2 : 1

[spoiler]what ratio are they talking about??

money spent or weight??

OA : B[/spoiler]

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Last edited by kamu on Wed Mar 11, 2009 11:52 pm, edited 2 times in total.
Source: — Data Sufficiency |

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Re: cheese from each Deli

by Ian Stewart » Wed Mar 11, 2009 3:37 pm
kamu wrote:Julian bought 6 kilograms of cheese from each Deli A and Deli B. At which deli did he spend more money on
cheese?
(1) The ratio of American to Provolone to Swiss purchased at Deli B was 2 : 7 : 2
(2) The ratio of American to Provolone to Swiss purchased at Deli A was 6 : 2 : 1

[spoiler]what ratio are they talking about??

money spent or weight??

OA : B[/spoiler]
Clearly more information is needed to answer the question, since the cost of the cheese isn't mentioned anywhere. Are the prices of the cheeses not mentioned in the question? And where is the question from? As written, the answer is clearly E, but you'd never see a similar question on a real GMAT, at least not without some mention of prices somewhere.
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by kamu » Wed Mar 11, 2009 11:58 pm
I'm sorry. I forgot to attach the image.
I've edited my post now.

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by Feep » Thu Mar 12, 2009 1:12 am
This question pulls the cheap trick of making statement (1) relate to Deli B and statement (2) relate to Deli A. Annoying.

Since we know an exact ratio, we can compute the average cost per kilogram of cheese from Deli A. $15 * (6/9) + $17 * (2/9) + $19 * (1/9) = $15.88. Now, even if ALL the cheese from Deli B is as cheap as it gets, we know that less money was spent at Deli A.

Trying this same trick with Deli B yields $16 * (2/11) + $18 * (7/11) + $20 * (2/11) = $18 (also obvious from symmetry). This does not yield enough information; the cost per kilogram from Deli A could be less, could be more.

So the correct answer is B.
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