In the figure above, what is the length of AD?

Question

https://gmatclub.com/forum/download/file.php?id=25103 In the figure above, what is the length of AD? (1) AC = 6 (2) BD = 6 2014-12-22_1955.png

uday1409 · Answer

1. CD is not known.Insufficient
2.AB is not known. Insufficeint

1+2 > > AB+2(BC)+CD=12 >> AD+BC=12
BC is not known. Insufficient

E

beattheheat · Answer

Determine the length of AD?

Statement 1: AC = 6
We don't know CD -- Insufficient

Statement 2: BD = 6
We don't know AB -- Insufficient

Combining 1&2:
AC + BD = 12, here BC is accounted twice and since we don't know BC -- Insufficient

Answer E

qw1981 · Answer

First thing you need to understand after looking at the figure position of points related to each other is not given. DO NOT ASSUME.

S(1): Tells nothing about CD hence N.S
S(2): Tells nothing about AB hence N.S

Event after combining we do not know distance between B & C which could be 6 or 0.01 . Hence Not sufficient.

I think this could have been a little more trickier if we were asked maximum length of AD will always be smaller then which number. The answer would be 12 assuming B&C are very close to each other and even if they are on top of each other the maximum length can be 12.

g106 · Answer

AD = AB+BC+CD

From Statement 1: AC =6; AD = 6+CD(We cannot find using given information)
Statement 2: BD = 6; AD= 6+AB (Again, We cannot find using given information)
Combining both also not sufficient to find the value

Ans : E

robinpallickal · Answer

Hi Bunnuel,

My soln was:

AD = AC + BD - BC (as in AC + BD , BC is already counted)
NOw as AC=BD = 6, both points B and C are same. ( Taking St 1 and St 2 together)

so AD = 12.

Can you Pls. guide me where I went wrong?

Bunuel · Answer

https://gmatclub.com/forum/download/file.php?id=25103 
The red part is not correct. Consider AB = 5, BC = 1, and CD = 5 OR AB = 4, BC = 2, and CD = 4.

GMATBusters · Answer

Try to draw the line diagram in mind to solve the question in seconds.
As we do not know the overlap of AC & BD, it is insufficient.

See the sketch.

amanvermagmat · Answer

We can also solve this question by taking AB=x, BC=y, CD=z. So we need to find AD, which is x+y+z

Statement 1:
Gives us x+y = 6, so it is not sufficient.

Statement 2:
Gives us y+z = 6, so again not sufficient.

Combining, we can add the two, we get:
x+y + y+z = 6+6 OR x+y+z + y = 12
Unless we know y, we cannot find x+y+z. So not sufficient.

Hence  E answer

dcummins · Answer

If we were told that A,B,C and D were equidistant then AD would equal 9.

But we aren't, so we cannot deduce that each distance is equal.

CD could equal 5 and BC could equal 1, so AD= 11 in this case.

Combined insufficient.

CEdward · Answer

We can jump straight to a combination of both.

Evidently, there is an overlap between the two regions, but we don't know how much overlap there is.

E.

bumpbot · Answer

Automated notice from GMAT Club BumpBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

In the figure above, what is the length of AD?

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Data Sufficiency (DS) Questions

In the figure above, what is the length of AD?

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards