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poonam1279
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This has been answered before - please search for the question.
- pradeep
what is the y-intercept of line
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Source: Beat The GMAT — Data Sufficiency |
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lunarpower
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(1)
y = mx + b
substitute m = 3b --> y = 3bx + b
this won't help us find b, so, insufficient.
(2)
graphically, we can draw a line through (-1/3, 0) with absolutely any slope we want. each of those lines will have a different y-intercept (with the exception of the one purely vertical line, which won't have a y-intercept at all).
insufficient.
(together)
substitute (-1/3, 0) into y = 3bx + b
0 = -b + b
0 = 0
this is a tautology, meaning that there is no further information to be learned from combining the two statements. in other words, the two statements are equivalent to one another.
for further proof of that equivalence, let's plug in the x-intercept of (-1/3, 0) only:
y = mx + b
0 = m(-1/3) + b
0 = (-1/3)m + b
(1/3)m = b
m = 3b
the slope is 3 times the y-intercept.
statement (2) is therefore equivalent to statement (1). since the individual statements are each insufficient, their "combination" (which really isn't much of a combination at all, because they're equivalent to each other) is still insufficient.
answer = (e).
y = mx + b
substitute m = 3b --> y = 3bx + b
this won't help us find b, so, insufficient.
(2)
graphically, we can draw a line through (-1/3, 0) with absolutely any slope we want. each of those lines will have a different y-intercept (with the exception of the one purely vertical line, which won't have a y-intercept at all).
insufficient.
(together)
substitute (-1/3, 0) into y = 3bx + b
0 = -b + b
0 = 0
this is a tautology, meaning that there is no further information to be learned from combining the two statements. in other words, the two statements are equivalent to one another.
for further proof of that equivalence, let's plug in the x-intercept of (-1/3, 0) only:
y = mx + b
0 = m(-1/3) + b
0 = (-1/3)m + b
(1/3)m = b
m = 3b
the slope is 3 times the y-intercept.
statement (2) is therefore equivalent to statement (1). since the individual statements are each insufficient, their "combination" (which really isn't much of a combination at all, because they're equivalent to each other) is still insufficient.
answer = (e).
Ron has been teaching various standardized tests for 20 years.
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Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
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Learn more about ron
