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parallel lines

by tonebeeze » Tue Jan 04, 2011 11:41 am
Which of the following lines parallel to line x = 1.44 - 3y?

a. y = x/6 + 25
b. y = 0.48 - x/3
c. x/3 - y = 2
d. y + x/3 = 10
e. x/4 + 3y =1

My answer was B

OA is D

Can some please explain the correct answer. Thanks
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by Everest » Tue Jan 04, 2011 11:52 am
Two lines are parallel if there slopes are equal.


Original line can be written as y = mx+c, where m is slope

x = 1.44 - 3y => y = -1/3x+1.44/3 => m = -1/3 (slope)


if we look at the choices both options B and D have slopes = -1/3.


IMO is B, D (There should be some mistake)
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by stormier » Tue Jan 04, 2011 11:53 am
tonebeeze wrote:Which of the following lines parallel to line x = 1.44 - 3y?

a. y = x/6 + 25
b. y = 0.48 - x/3
c. x/3 - y = 2
d. y + x/3 = 10
e. x/4 + 3y =1

My answer was B

OA is D

Can some please explain the correct answer. Thanks
You have the right idea - i.e. the slope of parallel line should be -1/3.

Choice B is the same line as the one in question stem (because the y intercept is also the same - 1.44/3 = 0.48)

Choice D is a "different" line with the same lope and is thus parallel to the line in question
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by Everest » Tue Jan 04, 2011 12:06 pm
A line cannot be parallel to itself. IMO is D
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by shovan85 » Tue Jan 04, 2011 12:19 pm
tonebeeze wrote:Which of the following lines parallel to line x = 1.44 - 3y?

a. y = x/6 + 25
b. y = 0.48 - x/3
c. x/3 - y = 2
d. y + x/3 = 10
e. x/4 + 3y =1

My answer was B

OA is D

Can some please explain the correct answer. Thanks
The answer should be D. As all of us clear on the concept that slope should be equal to be parallel, let me jump directly to Option B.

The equation in the Question is same as the equation in option B. Recently, in one of the experts reply (I think it was Rahul@Gurome) has stated that when two line equations are same that means those two Straight Lines are intersecting each other at MORE THAN ONE POINTS. And we know Parallel can NEVER intersect.

Thus, as Everest stated, Option B is NOT PARALLEL to the line we are considering.
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by anshumishra » Tue Jan 04, 2011 12:29 pm
tonebeeze wrote:Which of the following lines parallel to line x = 1.44 - 3y?

a. y = x/6 + 25
b. y = 0.48 - x/3
c. x/3 - y = 2
d. y + x/3 = 10
e. x/4 + 3y =1

My answer was B

OA is D

Can some please explain the correct answer. Thanks
The given equation of the line : x = 1.44 -3y
=> 3y = 1.44 -x
=> y = 0.48 - x/3

Now, this is same as "B". A given line can't be parallel to itself (Other way of saying what Shovan has just mentioned).
Hence "B" is not right.
Thanks
Anshu

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