GMAT Prep 2- Word Problem

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GMAT Prep 2- Word Problem

by caramel3536 » Fri May 09, 2008 2:07 pm
At the bakery, Lew spent a total of $6.00 for one kind of cupcake ad one kind of doughnut. How many doughnuts did he buy?
(1) The price of 2 donuts was $0.10 leass than the price of 3 cupcakes
(2) The average price of 1 doughnut and 1 cupcake was $0.35

ans (E)
Source: — Data Sufficiency |

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by akshatsingh » Sun May 11, 2008 10:37 pm
Let the Doughnuts be D each of price X
Let the Cupcakes be C each of price Y
DX+CY = 6.00

1) Says.. 3Y-2X= 0.10 Not Sufficient
2) Says.. X+Y = 0.70 Not Sufficient

Together, X and Y can be found out. But C and D cannot be found.


Answer E.
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clarification

by deltaforce » Tue Jun 23, 2009 8:01 am
does one kind mean type or quantity.. i assumed he bought one of each...
thanks

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by mohit11 » Thu Feb 25, 2010 10:09 pm
umm, i got this one wrong, but i am not convinced with the answer,


Let Price of Doughnut be D , number of Doughnuts - n1 , Price of Cupcake be C, number of Cupcakes - n2

So.. We have n1D + n2C = 6 (the total amount spent on Doughnuts and Cupcakes)

1. 2D =3C - 0.10 - Not Sufficient.

2. D+C/2 = 0.35 - Not Sufficient.

Taking both the equations together, we can find the value of D and C, but we don't have n1 and n2.

The answer should be E, however, i chose C, because..n1 and n2 can only be positive integers and there could only be one possible combination of n1 and n2 that would result in a total of 6 dollars. Hence C should have been the answer.

Can any experts throw some light on this?


Also, just to ellaborate my point, on how GMAT tricks mortals like us ..have a look at this question

https://www.manhattangmat.com/forums/mar ... t5144.html

So, is the criterion to decide between C and E in such questions is to check where you are on the Test, i.e. if it is in top 10, the answer is more likely to be C, if the question is 15+ then it is E.

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by stufigol » Fri Feb 26, 2010 12:02 am
6=xC+yD
with x the price of one Cake and y the price of one Don..
(1)+(2) --- we cand find that x=0.3 and y=0.4
he could have bought 6 Don and 12 cakes or 3 don and 16 cakes...(i m not quit sure if there are other sets) but just these two shows us that we can not be sure about the number of Don he bought ...=E
hope it helps

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by mohit11 » Fri Feb 26, 2010 12:04 am
Ya but that's the point, if go on to find two sets that would dismiss C as an option, you are essentially wasting approximately 5 minutes to solve the question.