Driver's license -- Overlapping sets

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by cramya » Thu Oct 23, 2008 4:47 pm
I think the cool thing about DS is even u get .70x=.20y which is not right still u would go for C and not E

We are not required to solve and waste time in DS questions
saving grace in a way).

If its a PS then I agree with u wholeheartedly!!!

Good luck!

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by rohangupta83 » Thu Oct 23, 2008 4:54 pm
yep, thanks mate. see you around.

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by Stockmoose16 » Thu Oct 23, 2008 5:31 pm
rohangupta83 wrote:damnit! i'm getting 2 different answers

either the answer is 200 or 105

Y = 200
X = 229 or 105

but 200 can't be the answer as the max could be 188 which is also not possible in this case so I'd go for 105!

I am not at all confident though..
Ok, I calculated it out.

X=160
Y=140

X+Y should not be equal to 188. If you look at your matrix, the following equations apply:

Y+.3X =188
X+.2Y=188

Y=7/8X

(you only need 2 of these formulas to solve)

The equation asks for the number of 16 yr olds who get their license.

The answer is .7x or .7 (160) =112

MGMAT says this is a 600-700 level question, but this appears to be much more difficult than that.

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by rohangupta83 » Thu Oct 23, 2008 5:35 pm
ahh thanks Stockmoose, glad the concept was in place. I must have been brain dead when I got those weird numbers.

from where did you get the 0.7x though?

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by Stockmoose16 » Fri Oct 24, 2008 11:15 am
rohangupta83 wrote:ahh thanks Stockmoose, glad the concept was in place. I must have been brain dead when I got those weird numbers.

from where did you get the 0.7x though?
The .7x came from the top left part of the matrix.

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by rumy » Sun Nov 16, 2008 7:52 am
This is a set problem .. when we have only A or only B the formula is
T=A+B+AB+n

here A=30%;B=20%;AB=?;n=0;suppose total = 100

Because this is an DS qs: we need both the parts to solve the problem.

Ans : C