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Bunuel
Are lines p (with slope m) and q (with slope n) perpendicular to each other?

(1) m + 2 = n
(2) m + n = 0


For the 2 lines to be perpendicular to each other, we need m*n = -1

Statement 1:
m + 2 = n
m- n = -2
Plug in numbers, m = -1, n = 1, we get m*n = -1...Hence lines are perpendicular
m = 1, n = 3, we get, m*n = 3...Hence lines are not perpendicular

Statement 1 alone is Not Sufficient.

Statement 2:
m + n = 0
m = -n
Plug in numbers, m = -1, n = 1, we get m*n = -1...Hence lines are perpendicular
m = 2, n = -2, we get m*n = -4...Hence lines are not perpendicular

Combining both statements, we get, m = -1 & n = 1, satisfying both the statements.
Hence m*n = -1. the lines are perpendicular.

Answer C.


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GyM
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Given: Line p has slope m and Line q has slope n.
To find: Are lines p and q perpendicular to each other?
For p and q to be perpendicluar m * n = -1

Statement 1:
m + 2 = n.
( m, n ) = ( 0, 2 ), ( 1, 3 ) ( -1 , 1 ) .....
So, statement 1 is insufficient.

Statement 2:
m + n = 0
( m, n ) = ( -2, 2 ), ( -3, 3 ) ( -1 , 1 ) .....
So, statement 2 is insufficient.

From Statement 1 and Statement 2:
Solving equations m - n = -2 and m + n = 0.
m = -1 and n = 1.
m * n = -1.
So, we can conclude that they are perpendicular.
Statement 1 and Statement 2 are sufficient.

Correct choice: C.
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Bunuel
Are lines p (with slope m) and q (with slope n) perpendicular to each other?

(1) m + 2 = n
(2) m + n = 0
Hi Bunuel,
I've a curiosity to know why this question is considered 700+ level question?
Is there any difficulty to solve this question?
Or,
Is there any other (serious things) that we need to consider to solve this problem?
Thanks__
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AsadAbu
Bunuel
Are lines p (with slope m) and q (with slope n) perpendicular to each other?

(1) m + 2 = n
(2) m + n = 0
Hi Bunuel,
I've a curiosity to know why this question is considered 700+ level question?
Is there any difficulty to solve this question?
Or,
Is there any other (serious things) that we need to consider to solve this problem?
Thanks__

The difficulty level of a question is calculated automatically based on the timer stats from the users which attempted the question.
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