A quadrilateral P has (1, 1), (3, 1), (3, 5) and (1, 5) as 4 vertices

Question

A quadrilateral  P  has  (1, 1), (3, 1), (3, 5)  and  (1, 5)  as  4  vertices and another quadrilateral  Q  has  (-1, -1), (-5, -1), (-5, -5)  and  (-1, -5)  as  4  vertices. A line divides these two quadrilaterals evenly at the same time. What is this line?

A.  y = \frac{- 1}{6}x + \frac{5}{6 } 
 
B.  y = \frac{- 5}{6}x + \frac{1}{6} 
 
C.  y = \frac{ 6}{5}x + \frac{3}{5} 
 
D.  y = \frac{1}{3}x + \frac{5}{6}  
 
E.  y = \frac{- 1}{6}x + \frac{7}{5}

GMATGuruNY · Accepted Answer

Each quadrilateral is a rectangle.
To divide a rectangle in half, a line must pass through the CENTER of the rectangle.

Center of P = (midpoint of the x-values, midpoint of the y-values)  = (\frac{1+3}{2}, \frac{1+5}{2}) = (2, 3) 
Center of Q = (midpoint of the x-values, midpoint of the y-values)  = (\frac{-1+(-5)}{2}, \frac{-1+(-5)}{2}) = (-3, -3)

The correct answer must pass through the two centers (2, 3) and (-3, -3).
Slope of the line that passes through (2, 3) and (-3, -3)  = \frac{∆y}{∆x} = \frac{-3-3}{-3-2} = \frac{6}{5}

C

MahmoudFawzy · Answer

By visualizing the two quadrilaterals, we find that one is in the first quadrant, and the other is in the fourth,
so for a line that can pass through them, the slope must be positive --->  this eliminates A,B,E

By trying D, the starting point of the line will be (3 , 1.833) which  can't be  possibly dividing the quadrilateral in the first quadrant.
By trying C, the starting point of the line will be (3 , 4.166) which can possibly do the trick
 C

MathRevolution · Answer

=> 1.9ps(a).png The quadrilaterals are rectangles, and bisecting lines of rectangles pass through the center of the rectangles. Thus we have to find the line passing through the centers of those two rectangles. The centers of the rectangles are (2, 3) and (-3, -3). The slope of the line passing through (2, 3) and (-3, -3) is \frac{(3- (-3)) }{ (2 - (-3))} =\frac{ 6}{5} . The line passing through them is y – 3 = (\frac{6}{5})(x - 2) or y = (\frac{6}{5})x + (\frac{3}{5}). Therefore, C is the answer. Answer: C

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A quadrilateral P has (1, 1), (3, 1), (3, 5) and (1, 5) as 4 vertices

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A quadrilateral P has (1, 1), (3, 1), (3, 5) and (1, 5) as 4 vertices

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