In the diagram above, what is the value of v?

IMO :-

If no data are provided about lines, we must not assume them as straight lines

But One Point which is always true :- angle around Point is 360

If line with x,y,z is assumed straight line then v =30* Option 1 Sufficient

If line with w,v,z is assumed straight line then x = 50*, But then we have to assume Line as bisector to arrive value for v (while v looks to be acute angle)- Not Possible

Combining both :- z=80*
If freedom of assuming straight line is given then Ans should be A

Simply from the diagram, x+y+v =180 degrees
From statement 1, x+y=150 degrees
Hence v=30 degrees
Statement 1 sufficient.

From statement 2, w+v=130 degrees
But, z+w=180 degrees.
If we do z+w-(w+v), which is z-v.
Thus z-v=50 degrees.
Nothing is given about z in statement 2.
So statement 2 is insufficient to determine v.

Hence IMO ans in A.

If a line appears to be straight in a GMAT diagram (whether in PS or DS), it is a straight line. Most GMAT geometry questions would be unanswerable otherwise.

So this diagram contains two long straight lines, and a third shorter line (between angles x and v). Since x, y and v are three angles in a straight line, they sum to 180, and Statement 1 thus lets us find the value of v (v is 30 degrees). Statement 2 lets us find x (x is 50 degrees) but no other angle, so the answer is A.

If it is assumed that these are two long straight line

Why it is not assumed than a line in between is angle bisector; then we will have a value of v from the second equation as 50*

And Ans will be D

If you were going to assume that, you'd also be obligated to assume that the two long lines bisect each other, and then there'd be no mystery whatsoever about the values of the angles -- they'd all be 90 degree or 45 degree angles, and you wouldn't even need the Statements.

If two lines meet at any kind of angle in a GMAT diagram, you cannot make any assumptions about the size of that angle. You need some information to reach any conclusions. But if you see something that looks like a straight line in a GMAT diagram, you can safely assume it genuinely is a straight line. It's never going to be two line segments that meet at a 179.99 degree angle that you can't see, or a curve with imperceptible curvature. If things that appear to be lines were sometimes not lines at all, many GMAT geometry questions with diagrams would be unanswerable.

OFFICIAL GUIDE:

Problem Solving
Figures: All figures accompanying problem solving questions are intended to provide information useful in solving the problems. Figures are drawn as accurately as possible. Exceptions will be clearly noted. Lines shown as straight are straight, and lines that appear jagged are also straight. The positions of points, angles, regions, etc., exist in the order shown, and angle measures are greater than zero. All figures lie in a plane unless otherwise indicated.

Data Sufficiency:
Figures:
• Figures conform to the information given in the question, but will not necessarily conform to the additional information given in statements (1) and (2).
• Lines shown as straight are straight, and lines that appear jagged are also straight.
• The positions of points, angles, regions, etc., exist in the order shown, and angle measures are greater than zero.
• All figures lie in a plane unless otherwise indicated.

Hope it helps.

Thanks, Sir
It is eyeopener

Thanks Bunuel
I missed Basic Directions of PS/DS

Will remember for long long time

v=?

From Diag. only thing we able to infer , z+w+y+x+v = 360
v = 360 - [ z+w+y+x ]

Statement 1: x+y = 150

v = 360 - [ z+w+150]
Not Sufficient


Statement 2 : w+v = 130

v = 360 - [ z+x+y+130-v]
Not Sufficient

Statement1 & Statement 2 :
From 1) x+y = 150
From 2) w+v = 130
thus , v = 360 - [ z+w+y +x]
v = 360 - [ 150+z+130-v ]
it cancelled out "v"

Not Sufficient

Both statement not sufficient to answer the question.
Answer(E)

In GMAT question,
* If It doesn't mentioned that the respective lines are straight even lines shows straight in diagram then also - we are not able to consider the line straight
* In Triangle also, if in diagram it shows like lines are perpendicular(90 deg or right angle triangle) we are not able to consider that if it didn't mentioned in question stem clearly.


Hope it helps.

In case this is confusing for other readers, the first thing you say above is not true. If a line appears to be straight in a GMAT diagram, it is a straight line.

The second thing you say is true: even if two lines appear to be perpendicular in a GMAT diagram, you cannot conclude that they are unless you have other information that establishes perpendicularity conclusively. Here I'm not including lines that are perpendicular by definition -- the x-axis and y-axis in a coordinate geometry diagram are automatically perpendicular, for example.

If the line is straight, and it should be assumed as straight, the answer must be A, as the 3 angles must sum to 180 and v equals 30.
statement B gives us the sum of x. we can not deduce the sum of V