If, on a coordinate plane, point A has the coordinates

Question

If, on a coordinate plane, point A has the coordinates (-3,4), how far is point A from point E?

(1) Point E is on the Y-axis, four units from the origin
(2) If point A were twice as far from point E, it would be the same distance from point E as point C is at coordinates (0,-2)

dwivedys · Answer

1) the point E could be on positive y axis at 4 units or negative y axis at 4 units. Insuff
2) clearly insuff because we dont know anything about E
combining - if point E is at positive y axis then A is at 3 units and doubling distance of A will make it 6 units - which is equal to distance of point E with respect to C which is at (0, -2). 
So only when E is in positive Y axis can this be true. Hence combining 1 and 2 gives the answer. C

Bull78 · Answer

I believe 1 is sufficient because it doesn't matter if it is negative nor possitive, in either way you can get the distance.

Please, somebody correct me...

gurpreetsingh · Answer

in either way you can find the distance, but you will get different answers with both the ways.

Since you cannot reach to a definite solution, the statement cannot be sufficient.

ulm · Answer

agree, it makes sense here.

Bull78 · Answer

It makes sense, but the question asks how far are the two points from each other. With statement 1 is possible to calculate two distances. Maybe I am trapped in GMAT rethorics, and need to get used to it.

Manythanks

Bunuel · Answer

Official Guide:

In data sufficiency problems that ask for the value of a quantity, the data given in the statements are sufficient only when it is possible to determine  exactly one numerical value for the quantity .

Hope it helps.

jlgdr · Answer

Whats the OA please? I thought the answer was B You can take the distance from A to C and that would be twice the distance from A to E, so just divide by 2 Answer is B Let us know please Cheers Happy thanksgiving! J

Caesar · Answer

B cannot be the answer since we do not know about point E

Suppose Point E has co ordinates (x,y)

Distance between Point E(x,y) and C(0, -2) = \sqrt{(y+2)^2 + x^2}
Distance between Point A(-3,4) and E(x,y) = \sqrt{(y-4)^2 + (x+3)^2} (By Distance formula)

Given 2(AE)=CE
so 2\sqrt{(y-4)^2 + (x+3)^2}= \sqrt{(y+2)^2 + x^2}
squaring both the sides
4((y-4)^2 + (x+3)^2) = ((y+2)^2 + x^2)
The above equation gives you an equation including x and y, that would be unsolvable further

Hope that helps..

mau5 · Answer

The distance between E and C is twice the distance between A and E. What you have assumed above is inorrect.

jlgdr · Answer

Yes, I understood what my error was. Tried it again and got it right this time Thank you all Cheers! J

abhishekmayank · Answer

From this statement :

If point A were twice as far from point E, it would be the same distance from point E as point C is at coordinates (0,-2)

It is difficult to deduce that : 2AE = CE

If, on a coordinate plane, point A has the coordinates

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GMAT Data Sufficiency (DS) Questions

If, on a coordinate plane, point A has the coordinates

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