M14, Q24

Question

If B, E , and A are not zeros, do lines Ax + By = C and Dx + Ey = F have the same slope?

A/B=D/E
E/B=D/A

The OA for this question is "D". But the question does not talk about "D", hence it can be zero. If D = 0 then D/E will be zero whereas A/B will not be zero (Since A, B are not zero's).

Hence i choose "E". Can somebody explain the logic behind the OA.

Thanks in Advance.

shuyin · Answer

A/B=D/E. While A#0 --> D #0. 
E/B=D/A. While E#0 --> D #0.

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GMATmission · Answer

Isn't it an unstated rule that if both the options are deadly twins, the answer is E. Or is it that this rule is ignored when we can find the answer using the options?

Can experts please comment as I intend to use this rule straighaway when I see deadly twins.

Saurajm · Answer

Initially went with answer D, but now, considering that it is also possible that D=0 i think that the answer should be E.......

what do you think? In these kind of questions, should I consider that 0 can be the numerator or not?

thanks

GMAT98 · Answer

If D=0 then statement 1 will not be true. But, we have to consider that statements are true. Therefore, D cannot be 0.

M14, Q24

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