gmat prep probabilty

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gmat prep probabilty

by [email protected] » Sat Aug 09, 2008 7:22 am
Anyone know why this is 1/6? my answer was 1/4.
My reasoning behind this was if you want the equation to be true any one of the values for x must = 0.
Therefore x could = 5, -10 or 2.5

So the probability of picking one of those number is 1/12 + 1/12 + 1/12 = 3/12 = 1/4.

Anyone know where I am going wrong. Thanks
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by raunekk » Sat Aug 09, 2008 7:55 am
you are goin correct...

d only thing u are missing is...

X can be 2.5 , 5 , -10

but if u see the elements in the set, 5 is missing...

so only outcomes of X in the set are 2.5 and -10

thus desired outcomes=2 (2.5 and -10)

and total number of elements in the set 12

prob= 2/12 = 1/6


i hope this helps..

thanks.