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necromonger
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GMATT73
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positive soul
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Necro - your tips are great...they are spot on actually. And I even use the good looking number guessing technique myself.
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deepak232
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necromonger, u are just another Rhyme for this forum...
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deepak232
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and i just downloaded your geometry quick sheet,,, took out its print out and stuck it on wall
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necromonger
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nice tip matt, I'll edit the original and add this as well. I guess if others can suggest nice tips we can sort of update the sticky...

GMATT73
You can add in "Lucky Twins" to your repertoire



*LUCKY TWINS
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necromonger
nice tip matt, I'll edit the original and add this as well. I guess if others can suggest nice tips we can sort of update the sticky...

GMATT73
You can add in "Lucky Twins" to your repertoire



*LUCKY TWINS


Can you post your geometry sticky/tips too?

Thanks!
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Regarding this problem, I think the answer is E.

Z is a multiple of 6. 678463 is not a multiple of 2 nor of 3, so it´s not a multiple of 6 either. Thus, Z could never be a divisor (factor) of 678463.


GMATT73
You can add in "Lucky Twins" to your repertoire

The purpose of this problem is to exploit a weakness used by PVue: complimentary answer choices. Almost always in complimentary probability questions, there are a pair of "LUCKY TWINS" among the answer choices. If in doubt and pressed for time, choose a TWIN by logical deduction.

Let`s take a crack at this Project GMAT bad boy without making lengthy calculations.

Set S consists of numbers 2, 3, 6, 48, and 164. Number K is computed by multiplying one random number from set S by one of the first 10 non-negative integers, also selected at random. If Z=6^K, what is the probability that 678,463 is not a multiple of Z?

a. 10%
b. 25%
c. 50%
d. 90%
e. 100%

*LUCKY TWINS
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Andr359
Regarding this problem, I think the answer is E.

Z is a multiple of 6. 678463 is not a multiple of 2 nor of 3, so it´s not a multiple of 6 either. Thus, Z could never be a divisor (factor) of 678463.


GMATT73
You can add in "Lucky Twins" to your repertoire

The purpose of this problem is to exploit a weakness used by PVue: complimentary answer choices. Almost always in complimentary probability questions, there are a pair of "LUCKY TWINS" among the answer choices. If in doubt and pressed for time, choose a TWIN by logical deduction.

Let`s take a crack at this Project GMAT bad boy without making lengthy calculations.

Set S consists of numbers 2, 3, 6, 48, and 164. Number K is computed by multiplying one random number from set S by one of the first 10 non-negative integers, also selected at random. If Z=6^K, what is the probability that 678,463 is not a multiple of Z?

a. 10%
b. 25%
c. 50%
d. 90%
e. 100%

*LUCKY TWINS


I would choose D base on the fact that one of the first 10 non-negative integers could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

If you randomly get 0, then Z = 6^0 = 1. and 1 is a multiple of 678,469. Thus, there is 10% that Z will become a multiple of 678,469 OR 90% (100% - 10%) that Z will not become a multiple of 678,468.
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This is very helpful and, believe me, I need all the help I can get!
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MuffE
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did anyone arrive at a final answer?
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h2polo
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This was a very useful post... Unique way of looking at some of the traps that GMAT sets out.

Thanks!

+1
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gottabwise
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I've been looking for tips and insight on traps so THANK YOU for the post. If you could have only seen how large my eyes got as I read the post...entertaining yet so real.
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mrblack
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thanks! i'm bookmarking this page for future reference.
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I enjoyed your post. I'm going to print this and use it for reference.
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Great post! Thank you!
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msand
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liked this post a lot...
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Is the answer for Lucky Twin question D?
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reachsb
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An eye opener. Thanks
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