Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of lone p ?
1- Lines n ans p intersect at the point (5,1)
2- The y intercept of line n is greater that the y intercept of line p
The answer is C). But why? look at the two differents cases where the intercept of line n and the intercept of line p are both negative or both positive: do we have the same answer ? thanks
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n's slope and p's slope
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Brent@GMATPrepNow
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Target question: Is slope of line n less than slope of line p?Lines n and p lie in xy plane. Is slope of line n less than slope of line p?
(1) Lines n and p intersect at (5, 1)
(2) the y-intercept of line n is greater than the y-intercept of line p
Statement 1: Lines n and p intersect at (5, 1)
We can use sketches to show that statement (1) is NOT SUFFICIENT
Statement 2: the y-intercept of line n is greater than the y-intercept of line p
We can use sketches to show that statement (2) is NOT SUFFIENT.
Statements 1 and 2 combined
Let n be the y-intercept of line n
Let p be the y-intercept of line p.
So, line n has the points (0,n) and (5,1).
And line p has the points (0,p) and (5,1)
IMPORTANT: We also know that n>p (from statement 2)
When we apply the slope formula, we get:
Slope of line n = (1-n)/(5-0)= (1-n)/5
Slope of line p = (1-p)/(5-0)= (1-p)/5
Since n>p, we know that (1-p)/5 (the slope of line p) WILL BE GREATER than (1-n)/5 (the slope of line n)
Since we can answer the target question with certainty, the combined statements are SUFFICIENT
Answer = C
Cheers,
Brent
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Max@Math Revolution
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Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and equations ensures a solution.
Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of lone p ?
1- Lines n ans p intersect at the point (5,1)
2- The y intercept of line n is greater that the y intercept of line p
==> Since we need the slope and y - intercept for a line, we are dealing with 2 variables here. But the original question asks for 2 lines, meaning we have 4 variables to deal with and require 4 equations to match the number of variables. Since there are only 1 equations in (1) and (2) each, we need 2 more equations and E is likely the answer. It turns out that E actually is the answer.
When we solve the question directly, if n has the slope of 1/2 and p has the slope of 2, then yes is the solution, b ut if n has the slope of -2 and p has the slope of 2 then the solution is no. Therefore the answer is E.
If you know our own innovative logics to find the answer, you don't need to actually solve the problem.
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l The one-and-only World's First Variable Approach for DS and IVY Approach for PS that allow anyone to easily solve GMAT math questions.
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Lines n and p lie in the xy-plane. Is the slope of line n less than the slope of lone p ?
1- Lines n ans p intersect at the point (5,1)
2- The y intercept of line n is greater that the y intercept of line p
==> Since we need the slope and y - intercept for a line, we are dealing with 2 variables here. But the original question asks for 2 lines, meaning we have 4 variables to deal with and require 4 equations to match the number of variables. Since there are only 1 equations in (1) and (2) each, we need 2 more equations and E is likely the answer. It turns out that E actually is the answer.
When we solve the question directly, if n has the slope of 1/2 and p has the slope of 2, then yes is the solution, b ut if n has the slope of -2 and p has the slope of 2 then the solution is no. Therefore the answer is E.
If you know our own innovative logics to find the answer, you don't need to actually solve the problem.
www.mathrevolution.com
l The one-and-only World's First Variable Approach for DS and IVY Approach for PS that allow anyone to easily solve GMAT math questions.
l The easy-to-use solutions. Math skills are totally irrelevant. Forget conventional ways of solving math questions.
l The most effective time management for GMAT math to date allowing you to solve 37 questions with 10 minutes to spare
l Hitting a score of 45 is very easy and points and 49-51 is also doable.
l Unlimited Access to over 120 free video lessons at https://www.mathrevolution.com/gmat/lesson
l Our advertising video at https://www.youtube.com/watch?v=R_Fki3_2vO8
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Max@Math Revolution
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Wrong reading of the question. Yes, you are correct. Thanks for catching.
No. of variable is 4 so E is liklely to be the answer in most cases.
But in this question, C is the answer.
No. of variable is 4 so E is liklely to be the answer in most cases.
But in this question, C is the answer.
