If four lines intersect as shown in the figure above, what is the

Question

https://gmatclub.com/forum/download/file.php?id=37149 If four lines intersect as shown in the figure above, what is the value of (x + y)? (A) 140 (B) 130 (C) 120 (D) 110 (E) 100 2017-08-24_1249_002.png

broall · Answer

2017-08-24_1249_002.png As the image above, we have: x = 70 - 30 = 40 y = 180 - x - 60 = 180 - 40 - 60 = 80 x + y = 40 + 80 = 120 Answer C

Nikkb · Answer

we have to find x+y

Here x+y is sum of exterior angle which is 180-(30+30) =120

Answer: C

For understanding properly refer to attached figure :

In Triangle ABC
Sum of x+y = exterior angle = Angle DCE

Angle DCE = 180-30-30 =120

Therefore x+y = 120

(No need to use angle 70 here )

Answer C

pushkarajnjadhav · Answer

Hii,
Here is my solution.

Kudos if it helps.

ScottTargetTestPrep · Answer

We can see there are several triangles in this diagram, but let’s only concentrate on two of them. The first one (the smaller one) is the one with the two 30-degree angles. The second one (the larger one) is the one that is composed of the triangle with the x-degree angle and the quadrilateral with the y-degree angle.

In the larger triangle we’ve described above, we see that it has the x-degree and the y-degree angle, and the remaining angle (unlabeled) is actually an exterior angle of the smaller triangle we’ve described above. Recall that an exterior angle of a triangle is equal to the two remote interior angles of the triangle. Thus, this unlabeled angle of the larger triangle is equal to the sum of the two 30-degree angles of the smaller triangle, which is 60 degrees. Thus, we have:

60 + x + y = 180

x + y = 120

Alternate Solution:

Let’s look at the smaller triangle, the one that has x as one of its interior angles. Another interior angle of this triangle is 30, and the remote exterior angle is 70. Since an exterior angle is the sum of the two remote interior angles, x + 30 = 70, and thus x = 40.

Next, let’s look at the triangle that has y and 30 as two of its interior angles. The remaining interior angle is found to be 70, and since the interior angles add up to 180, we must have y + 30 + 70 = 180. Then, y = 80, and thus x + y = 40 + 80 = 120.

Answer: C

bumpbot · Answer

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If four lines intersect as shown in the figure above, what is the

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