Let x and y be positive integers, and r and s be single-digit positive

Concentrating only on the answer choices, only option D is not a multiple of 3. The rest of them are multiples of 3, thats a common trend in other answer choices. With this logic can we say that Option D is correct answer?

Cheers,
Sri

Hi Sri,

I would say YES, you can conclude it but only in grave situations when you have already given up on question and have to move on with one of the answer choices as selection.

For such questions... generally one rule works most of the time
if there is only 2 or 5 or combination of 2 and 5 in denominator, it will always give u a fixed output rather than a never ending one.
You can try few examples

33/5 = 6.6
3333333333/5 = 666666.6 something

1111/2 = 555.5


in all options except D, there is a factor of 3 involved... where as in D only 5 is there (5*5 = 25)
in GMAT you dont need to solve every expression... there might be possibility of other options as correct but first skim through options and then use logic.
I have solved numerous questions of gmat but never felt the need to solve anything for such questions..

yes, if still you want to use logic, then a perfect algebric solution is provided by GMATINSIGHT

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