Can anyone explain this answer?

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Can anyone explain this answer?

by madsport » Tue Sep 09, 2008 9:51 am
The answer is E
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sd question 6 test 28.JPG

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by mlane25269 » Tue Sep 09, 2008 10:05 am
Hi Madsport!

Statement 1 only gives us the length of AC

Statement 2 only gives the length of BD

Since there is no information about the length of BC and because we can NEVER assume that lines or figures are drawn to scale in data sufficiency questions, there is no way for us to find the length of BC and thus length of line AD.

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by canuckclint » Thu Sep 11, 2008 10:23 pm
Divide the segments into x, y, and z, three parts, we want total t

Then x + y + z = t

1. x+ y =6
2. y + z = 6

3 equattions 4 unknowns x,y,z and t, impossible to solve,
PS. we can get rid of y by subtracting the eqautions.

4. x - z = 0
We could get x = z, but when we plug into 1., we get 2 back:
z + y = 6.