Can DS Statements Contradict themselves ?

[ManjunathD921]

Can the DS Statement 1 contradict with DS Statement 2 or Vice -versa

For Yes/No Question:
- Statement 1 yields a definite "Yes" and Statement 2 yields a definite "No"

For Find the Value Questions
- Statement 1 yields a single value for a variable "x" and Statement 2 yields again a single value but the value is different from what was arrived from Statement2

Can the above scenario possible?

Please let me know

Thanks,
Manju

[tim]

This is not possible. The most practical implication is that if you feel the statements contradict each other in a particular question, you have definitely made a mistake somewhere and need to check your work.

[RonPurewal]

yep.

...although, in practical terms, there's no easy way to tell which statement you've handled incorrectly. life is that way sometimes.

[RonPurewal]

...actually that's not quite true. there is ONE guideline you can use:
'no = sufficient' is EXTREMELY rare on DS problems.
in the entire 13th/2015 OG there is only ONE such problem (DS #136)... and that one problem has actually been omitted from the 2016 OG!

so...

For Yes/No Question:
- Statement 1 yields a definite "Yes" and Statement 2 yields a definite "No"

...therefore, if you see this ^^ then, empirically, it is virtually certain that you've make a mistake with statement 2.

(note: there is absolutely no logical reason why this would be so. this is purely an observation of the habits GMAC follows in creating the problems.)

[RonPurewal]

also, there's a corollary observation:
because 'no = sufficient' is so rare, it follows that if you can get 'no' to happen, the statement is almost certainly INsufficient.

basically, the logic is this:
• if you make 'no' happen, then there are 2 possibilities: /1/ 'no = sufficient' or /2/ 'insufficient'.
• possibility #1 is vanishingly rare.
• therefore #2 almost certainly obtains.

of course it's better to actually solve the problem (!!)... but, if you find yourself in a time crunch, then this is something you can whip out.

[ManjunathD921]

Thanks for the reply. I checked back on few questions from OG which i had done mistake.
And as you said there is no general rule for this, it is just how GMAT test makers have framed the questions.

[RonPurewal]

yep.