There is a widespread belief in the US and Western

[RonPurewal]

I got questions about ambiguity. What if I didn't find the ambiguity when solving the problem?

this is a good question. fortunately, the problems are written specifically to help you in this regard.

if 'ambiguity' is an issue, then...
...1/ it will be THE ONLY DIFFERENCE between the correct answer and an incorrect answer,
AND
...2/ it will involve the inclusion/exclusion of some 'little' word (a helping verb such as 'had', or a preposition such as 'to', or something else along those lines).

[RonPurewal]

if 'ambiguity' is an issue, then...
...1/ it will be THE ONLY DIFFERENCE between the correct answer and an incorrect answer,
AND
...2/ it will involve the inclusion/exclusion of some 'little' word (a helping verb such as 'had', or a preposition such as 'to', or something else along those lines).

the blue thing is the most important thing.
clearly you would not want to waste your time thinking about 'ambiguity' in random problems.

...but, here, look at the two choices that differ ONLY in the inclusion/exclusion of 'had'.
that's a pretty clear indication that you should think about ambiguity here.
sure, you might think for a moment about whether 'had' is correct. but, as soon as you ascertain that it is, what else would you possibly think about?

[RonPurewal]

fyi, you can see exactly the same thing at work in problem #103 in the second edition OG verbal supplement / #112 of the new 2016 supplement ('Inuits of the Bering Sea').
this is for reference only; please do not cite or discuss the OG problem here. thanks.

[sdfsdfsdfs481]

Thanks for your tips.

It is good to look at the differences. And what come up in my mind is that usually the difference looks like a reminder to let you notice there could be an ambiguity exist, and usually it does.

fyi, you can see exactly the same thing at work in problem #103 in the second edition OG verbal supplement / #112 of the new 2016 supplement ('Inuits of the Bering Sea').
this is for reference only; please do not cite or discuss the OG problem here. thanks.

[RonPurewal]

a reminder to let you notice there could be an ambiguity exist

that is EXACTLY the point.

this test has fairly strict timing.
so, 'you must constantly watch out for ambiguity' would be an unreasonable expectation. (in theory, 'ambiguity' could exist almost anywhere at all.)

if you DO have to see ambiguity, then GMAC will write answer choices that say Hey you! Yeah, you! You need to think about ambiguity now, BECAUSE THERE'S NOTHING ELSE TO THINK ABOUT.

[RonPurewal]

Thanks for your tips.

It is good to look at the differences. And what come up in my mind is that usually the difference looks like a reminder to let you notice there could be an ambiguity exist, and usually it does.

the red thing is correct, but DO NOT JUST ASSUME IT.

first, do a QUICK check for BIG PROBLEMS with the added word(s).
BIG PROBLEMS include:
• non-parallelism
• nonsense meanings
• grammatical disagreement (subject-verb, pronoun-noun, etc.)

e.g., if the added word in this problem were 'has' (rather than 'had'), there would be two HUGE problems:
1/ 'parents and grandparents has' = plural subject, but singular verb;
2/ the present tense is clearly nonsense here.

here, there are no HUGE PROBLEMS with 'had'. this is the signal that it's time to start thinking about ambiguity.

[sdfsdfsdfs481]

I agree with you. Always check from big problems first!

Thanks for your tips.

It is good to look at the differences. And what come up in my mind is that usually the difference looks like a reminder to let you notice there could be an ambiguity exist, and usually it does.

the red thing is correct, but DO NOT JUST ASSUME IT.

first, do a QUICK check for BIG PROBLEMS with the added word(s).
BIG PROBLEMS include:
• non-parallelism
• nonsense meanings
• grammatical disagreement (subject-verb, pronoun-noun, etc.)

e.g., if the added word in this problem were 'has' (rather than 'had'), there would be two HUGE problems:
1/ 'parents and grandparents has' = plural subject, but singular verb;
2/ the present tense is clearly nonsense here.

here, there are no HUGE PROBLEMS with 'had'. this is the signal that it's time to start thinking about ambiguity.

[RonPurewal]

Always check from big problems first!

this ^^ is sound advice not just for 'ambiguity', but for SC as a whole.

if the choices are 'weird', then that 'weirdness' will almost always be paired with VERY straightforward eliminations.
i wrote about this here:
https://www.manhattanprep.com/gmat/foru ... ml#p117778

GMAC really is fantastically good at writing problems that do NOT require weird obscure bits of knowledge.