Data Sufficiency

Ian Stewart wrote:

sivaelectric wrote:What number is 30% of a?

1. 20% of a is 100
2. 300 is of a

The second statement above is clearly incomplete. The issue with the question is not that the statements are contradictory; the problem is that the sentence "300 is of a" is completely meaningless. It does not mean that 300 is equal to a, as you seem to have interpreted it. I don't know whether the error exists in the original source material, but there are clearly words missing; I imagine it is supposed to read "300 is 60% of a" or something similar.

That's there Ian, very true; but what about the suggestion "that you dont have to get the same answer and you just need to find whether the given is suitable to solve the question or not.", which I have quoted on purpose? Isn't that any issue? Please enlighten

Sanju -


Both are correct - on the GMAT it is enough to KNOW that you can solve. Notice that I said KNOW that you can solve it. Not "hope" you can or "believe" you can - but know it.

Now if there is a doubt as to whether you have covered all of your bases and considered all of the possibilities then you need to make sure that the two statements give you the possibility of the same answer. On the GMAT there is always at least one number in common between the two statements.

So you are right -- If you know that you can solve it there is no need to, but if you are in doubt then solve it and make sure the statements can be true at the same time.