Dear nahid78,

I'm happy to respond.

The big idea here is that if a time interval is unmodified, then we typically use "in" or "for." Notice, that the modifiers such as "more than" or "less than" don't change the basic pattern.
In three days, I will do X
In less than two years, I will do X.
For more than six years, I did X.
BUT, and this is very important, when the the time interval is modified, by a preposition or a clause, we do NOT need a preposition.
Three days after the wedding, I did X. = preposition modifier
More than six years before the French Revolution, he did X. = preposition modifier
Less than five minutes after you called, I did X. = clause modifier
Two days before you returned to town, I did X. = clause modifier

In this sentence, the time interval "three years" is modified by a clause beginning with a subordinate conjunction ("after" in (A) and "since" in (C)). Because it's modified in this way, it does not need a preposition.

Does all this make sense?
Mike
_________________

Dear Friends,

Here is a detailed explanation to this question-

Meaning is crucial to solving this problem:
Understanding the intended meaning is key to solving this question; the intended core meaning of this sentence is that less than 35 years after African honeybees were released outside Sao Paulo, the bees' descendants had migrated as far north as southern Texas.

Concepts tested here: Meaning + Modifiers + Pronouns + Awkwardness/Redundancy

A: Correct. This answer choice uses the phrase "Less than 35 years after the release of African honeybees outside Sao Paulo" to modify the clause "their descendants...had migrated as far north as Southern Texas", less than 35 years after African honeybees were released, by someone else, outside Sao Paulo, the bees' descendants had migrated as far north as southern Texas. Further, Option A avoids the pronoun error seen in Options D and E, as it uses no pronouns. Additionally, Option A is free from awkwardness and redundancy.

B: Trap. This answer choice alters the meaning of this sentence through the phrase "less than 35 years since releasing"; the construction of this phrase incorrectly modifies "their descendants", incorrectly implying that the African honeybees released their descendants outside Sao Paulo; the intended meaning is that someone else released the African honeybees outside Sao Paulo. Additionally, Option B uses the needlessly wordy phrase "In less than", leading to awkwardness and redundancy; this usage is redundant, as "In" can be deleted without a loss of clarity.

C: Trap. This answer choice redundantly uses the past perfect tense verb "had been released" alongside the word "since"; remember, when the chronology is clear because of terms such as "before/after/when/earlier/later"…or because of clear mention of dates, use past perfect tense is not required, though not incorrect either. Further, Option C uses the needlessly wordy phrase "In less than the", leading to further awkwardness and redundancy.

D: This answer choice alters the meaning of the sentence through the phrases "It took less than" and "when their descendants...Texas"; the construction of these phrases incorrectly implies that the descendants of African honeybees had migrated as far north as Southern Texas, at the same time as the release of African honeybees outside Sao Paulo, and some unspecified event occurred less than 35 years later; the intended meaning is that less than 35 years after African honeybees were released outside Sao Paulo, the bees' descendants had migrated as far north as southern Texas. Further, Option D suffers from a pronoun error, as the pronoun "It" lacks a clear referent.

E: This answer choice alters the meaning of the sentence through the phrases "It took less than" and "and then their descendants...Texas"; the construction of these phrases incorrectly implies that some unspecified event took place less than 35 years after African honeybees were released outside Sao Paulo, Brazil, and after that event, the bees' descendants had migrated as far north as Southern Texas. Further, Option E suffers from a pronoun error, as the pronoun "It" lacks a clear referent. Additionally, Option E redundantly uses the past perfect tense verb "had been released" alongside the word "then"; remember, when the chronology is clear because of terms such as "before/after/when/earlier/later"…or because of clear mention of dates, use past perfect tense is not required, though not incorrect either. Besides, Option E uses the needlessly wordy phrase "after the time that African honeybees were released", leading to further awkwardness.

Hence, A is the best answer choice.

All the best!
Experts' Global Team
_________________

What did you think of the original sentence?

My first reaction was: wait, what? Why does it say “had migrated?” That sounded not-quite-right to me. Of course, that portion of the sentence isn’t underlined, so it has to be right!

So I realized I have one of two things, here: either I need to fix some problem in the underlined portion or this is a hard problem and they just tricked me into thinking it “sounded funny” when there’s nothing wrong with it.

In general, when you think something sounds funny, go figure out what specific rule is being broken, or whether the meaning is illogical or ambiguous. If you can’t find anything, then maybe your ear just fooled you.

So, let’s examine this. Why was I surprised by the usage of “had migrated” in the non-underlined portion? What is that – what part of speech? How is it supposed to be used?

“Had migrated” is a verb tense construction. Specifically, it’s an example of the past perfect tense, which is a complex past tense construction. We use past perfect in one specific situation: when we have two (or more) actions taking place at different times in the past, and we want to indicate which one happened before the other.

We use past perfect to indicate the older, longer-ago action and either present perfect or a time marker to indicate the not-as-old action or timeframe. For example:

Before the age of 30, she had changed careers three times.

When she decided to go to graduate school, she had already changed careers three times.

In both sentences, the action that occurred first was the act of changing careers. First she changed careers three times, then she turned 30. First she changed careers three times, then she decided to go to graduate school. All of these actions are in the past, but some happened earlier than others in the past.

In the first sentence, we have a time marker to indicate the later timeframe or action: “before the age of 30.” In the second sentence, the later action is indicated by the simple past tense: “she decided.” Both of these constructions are acceptable to indicate the later of the two events or timeframes.

In both sentences, we see the same past perfect construction: “she had changed.” To construct the past perfect, we always begin with the word “had” and then we add the past participle of the verb we want to use. Regular past participles end with the letters “ed”: had changed, had worked, had played. There are also irregular past participles: had eaten, had gone, had seen.

Let’s go back to our original problem. The non-underlined portion contains “had migrated,” so the underlined portion must contain either a time marker or an action presented in the simple past tense. And here’s where our ear can be fooled.

Many people will naturally think of the action as the release of the honeybees. First, they were released; later, they migrated. That’s certainly true, and if the sentence had used the verb form of the word “release,” then answer A would be wrong. But the word “release” is in noun form in the sentence. We don’t have any verbs in the simple past tense at all. Instead, we have a time marker.

What is the time marker? “Less than 35 years after.” Did the migration of the honeybees occur before or after “less than 35 years after?”

Before! First, the bees were released. Then, they migrated north. Finally, it was “35 years after” the release, by which time the bees had already migrated. This is a similar construction to our “before the age of 30” time marker above. Let’s try another example.

Less than 10 years after her graduation from college, she had changed careers three times.

It still sounds a little funny doesn’t it? It’s the “less than” that’s key: the action that occurs after the comma (“she had changed”) occurs less than 10 years after her graduation. The changes occurred before that 10 years passed.

Okay. So the tense “problem” in the original sentence is not a problem at all. I don’t immediately see anything else wrong with the original, and I also have an idea of how they’re going to change some of the other answers (they’re going to want to try to set the trap for those of us who think the tense is wrong), so I decide at this point to go look at the other answers. I’m thinking specifically about how they might mess up the meaning of the sentence using verb tenses – since they almost got me to think that the meaning of the original sentence was wrong by using what seemed at first like the wrong tense.

Answer B doesn’t contain a regular tensed verb. Answer C does, though! It says the bees “had been released.” So, let’s see, the release happens first. That does make sense, because you have to release them before they can migrate. Then the migration happens after that, so we need to go change that tense to simple present… oh, wait, we can’t. It’s not underlined.

If I leave both “had been released” and “had migrated” in the past perfect tense, then the sentence is saying that these things both happened at the same time. That doesn’t make sense (illogical meaning!), so answer C is incorrect.

Bonus Question: what’s the difference between saying “had been released” and “had released?” (Answer at end.)

Answer D doesn’t contain a tensed verb, but answer E does. This answer says the bees “were released,” which is simple past. This would mean that the bees first migrated and then were released – again, messed-up meaning! Eliminate E.

We’ve narrowed the answers to A, B, and D. I noticed something about B when I was looking for tensed verbs. It says “since releasing honeybees…”

Less than 10 minutes after releasing a helium-filled balloon, the child could no longer see it in the sky.

The word “releasing” is indicating an action performed by someone or something. Someone or something is releasing (or was releasing) the balloon. That someone or something has to be placed after the comma (this is a standard noun-modifier construction). If I want to talk about the balloon after the comma, then I need to change the structure:

Less than 10 minutes after being released, the helium-filled balloon had floated out of sight.

The child is releasing the balloon, but the balloon is being released.

Okay, so that eliminates answer B, because it can’t be the case that the descendants of the African honeybees were the ones releasing their ancestors! We’re down to A and D.

Let’s look at D more closely. What’s the difference between answer D and these sentences:

It took less than 35 years for the lazy student to finish business school.

It took less than 35 years to mow the lawn.

“It took less than 35 years” is the same in all of the sentences, of course. What about the rest of the sentences?

The construction “it took less than <some amount of time>” needs to be followed by “for <something to occur>” or “to <do something>” at some point in the sentence. These are idioms. Logically, the “something to occur” in our problem is the migration of the bees. Answer D, though, uses “when” to introduce the part about the migration. Try that out in the simpler sentence construction:

It took less than 35 years, when the lazy student had finished business school.

I’m still waiting for them to tell me what took less than 35 years! It took less than 35 years, when the lazy student had finished business school, to find a job?

Whatever it is, the structure of D is incomplete because I don’t know what took less than 35 years to do or occur. The correct answer is A.

Answer to Bonus Question: “Had released” represents active voice and “had been released” represents passive voice. I had already released my little brother 10 minutes before my mom came home and yelled at me for teasing him. My little brother had already been released by me before…

We use active voice when the subject is performing the action: I ate the pizza. We use passive voice when the subject is having the action performed on it: The pizza was eaten by me.
_________________

Go with A


B. In less than 35 years since releasing African honeybees outside Sao Paulo, Brazil, -- Since is incorrect - coz since means from a point of time to till date.
C. In less than the 35 years since African honeybees had been released outside Sao Paulo, Brazil,-- same as B
D. It took less than 35 years from the release of African honeybees outside Sao Paulo, Brazil, when -- from.. when unidiomatic. and pronoun it is unnecessary
E. It took less than 35 years after the time that African honeybees were released outside Sao Paulo, Brazil, and then -- same as D

http://www.manhattangmat.com/forums/gma ... t1864.html

^Description of answer. Tough question:>>

wait wait wait, how has nobody commented on the phrase "popular known as" in the original sentence. i am assuming OP made a typo and this was to be "popularly known as"

i would say best answer is also A. C is just very wordy to me, both a and c are saying the same thing in essence.

just my own opinion

Really good question !
Demonstrates how a past perfect tense can be used in a sentence without the use of simple past preceeding it ... I hate exceptions !
_________________

First, please make sure that you post the original sentence correctly! The non-underlined part doesn't make sense as written. The sentence should read:



There's nothing glaringly wrong with the original, so we should either confidently pick it or scan the choices looking for differences.

If we choose to scan, we see that one difference is the opening phrase.

Let's combine the opening phrase with the final one, ignoring the parenthetical comments:

A) Less than 35 years after the release of X, their descendants had migrated as far as Y.

Sounds good!

B) In less than 35 years since releasing X, their descendants had migrated as far north as Southern Texas.

"Their descendants" doesn't modify those who did the releasing, so "since releasing" is wrong - eliminate.

C) In less than the 35 years since X had been released, their descendants had migrated as far north as Southern Texas.

"In less than the 35 years" is idiomatically incorrect. The proper idiom would be "In the less than 35 years" - and would change the meaning of the sentence - eliminate.

D) It took less than 35 years from the release of X, when their descendants had migrated as far north as Southern Texas.

"when" must refer to a time period; "it took less than 35 years" isn't a time period - eliminate. (The author could have said "It took less than 35 years from the release of X for their descendants to migrate as far as Southern Texas.)

E) It took less than 35 years after the time that X were released and then their descendants had migrated as far north as Southern Texas.

So many errors, so little time! The whole thing sounds horrible (always a good reason to eliminate a choice), the tenses don't make any sense and "it took less" certainly doesn't go with "and then" - eliminate.

A. ..after the release .. had migrated
B. ..since releasing .. had migrated
C. ..had been released .. had migrated
D. ..from the release .. had migrated
E. ..were released out.. had migrated

all the options apart from A have tense agreement problem

Let me give you my humble opinion.

B incorrect because, in part, of the misplaced modifier rule: whatever "releasing" is referring to needs to follow the comma after Brazil. However, "their descendants" (of honeybees) is unacceptable for obvious reasons.

C incorrect because "since" must be followed by an event at a particular point in time in the past (i.e, since 2000; since the release of the honeybees, since the honeybees were released). For this reason, the past perfect is inappropriate and you must use the simple past if you opt for a conjugated verb. Do NOT use the past perfect in the "since" clause, period. Also using "the" before 35 years is incorrect.

D and E incorrect:
D and E do not need any serious discussion as they offer an awkward sentence construction not used in English. Avoid that construction at all times (it... ,when or it...,and then)
Also "from" in D and "after the time" are not adequate in this context.

A is the correct answer.
Less than 35 years is enough-No need of the beginning "in".
A great way to check whether A is correct is to have the two clauses switch places; begin with the main clause "their descendents, popular known as killer bees had migrated as far north as Southern Texas and finish with the subordinate clause "less than 35 years after the release of African honeybees outside Sao Paulo, Brazil". This gives us:

Their descendents, popularly known as killer bees, had migrated as far north as Southern Texas less than 35 years after the release of African honeybees outside Sao Paulo, Brazil.
This is indeed a correct sentence.

Now, try the same technique with the other choices and tell us whether you like the resulting sentence. Which seems the most natural and fluid to you?
Finally, if A ain't broken, don't try to fix it.

I hope this helps.
Bye now.

Less than 35 years after the release of African honeybees outside Sao Paulo, Brazil, their descendents, popular known as killer bees had migrated as far north as Southern Texas.

A. Less than 35 years after the release of African honeybees outside Sao Paulo, Brazil,
Less ~ is adverbial phrase modifying the next whole sentence, Correct.

B. In less than 35 years since releasing African honeybees outside Sao Paulo, Brazil,
Releasing has no subject.

C. In less than the 35 years since African honeybees had been released outside Sao Paulo, Brazil,
sounds like the African honeybees has been released at the same time as the killer bees had migrated.
Making no sense.

D. It took less than 35 years from the release of African honeybees outside Sao Paulo, Brazil, when
'When' makes the sentence sound like at the time which the honey bees were migrated, the release happened. no sense.

E. It took less than 35 years after the time that African honeybees were released outside Sao Paulo, Brazil, and then

'and then' sounds like there's a time sequence. The release -> migration. No sense.
_________________

Hello mikemcgarry,
How are you?
I am stuck. can you please help me out?
I could eliminate D and E.
I also eliminated B, as I thought "the release of" is better than "releasing"
Did not understand the difference between "since" and "after"
I picked C, as I thought "in" was needed, and As honeybee "was released" first then The "migrated".
I think the pronoun "their" plays a role here, So i also hope that you might say something about pronoun too...

Thanks a ton in advance.
Respect...
_________________

Dear Mike,

I'm little bit confused about 'less than' in this question.

Why do not we use ' fewer than 3 years'? Is not 'years' countable word?

Thanks

Dear Mo2men,

I'm happy to respond.

The general rule, as you well know, is "fewer" for countable nouns and "less" for uncountable nouns.

A curious idiomatic exception to this pattern concerns units. Some units are so frequently used that they are, as it were, proxies for what they measure. Of course, the unit themselves are countable, but what they measure is typically uncountable. Thus
"less than $10" really means "less money than $10"
"less than seven hours" really means "less time than seven hours"
"less than five miles" really means "less distance than five miles"
"less than 25 lbs" really means "less weight than 25 lbs"

You see, when we are talking about a time of about 3 years, we are not really talking about three separate countable things: we are just talking about a continuous bulk of time. We would only talk about years as countable, say, if were were talking about something that very specifically happened just once a year, such as a big annual award. For example,
For the eight years inclusive from 1938 to 1945, the Nobel Peace Prize was awarded in fewer than half of those years.
In this context, the each year is a separate and countable thing. This is not how we are talking about time when we just want to know, how long did X last?

That last paragraph deals with subtleties far beyond what the GMAT is likely to test.

Does all this make sense?
Mike
_________________

Yes I understand now.
Thank you very much.
But can you please share something about the use of "past participle" in option "C". Is C wrong because of the preposition "In" or "had been released" is also wrong?
Thanks again...
_________________

Dear nahid78,

I'm happy to respond.

There's absolutely nothing wrong with the grammar in (C)--it's 100% grammatically correct. It's just a bit wordy, a longer and less powerful way of saying the same thing that (A) says, but (A) is sleek, efficient, and direct.

Grammar is only one of the considerations on the GMAT SC. The GMAT loves to construct grammatically correct options that are wrong because of logical or rhetorical problems.

Does all this make sense?
Mike
_________________

Dear Mike,

I got confused by your reply above about choice C. You just have eliminated C in earlier post because 'when the the time interval is modified, by a preposition or a clause, we do NOT need a preposition.'

Also, is the following construction grammatically correct?

since+past perfect, main clause with past perfect.

As I learned before, 'since' is used to give it must refer to a DEFINITE MOMENT in the past such as: since June, since 1990

Can you clarify please?

Dear Mo2men,

I'm happy to respond.

We are going deep down the rabbit hole of idioms here--technicalities far beyond what the GMAT expects you to know. We can use "years" without a preposition
Less than 35 years since . . . = concise & elegant
It's a little awkward to have just the preposition
In less than 35 years since . . . = not 100% wrong, but a little off
BUT, if we add the definite article, then we get a construction that sounds very sophisticated:
In less than the 35 years since . . . = correct & sophisticated, but more wordy
The definite article reifies that block of time, turns it into a definitive single lump of something. This is a very elegant way of speaking, very sophisticated, although admittedly, it's a bit wordy. It's a little more typical of highly adorned academic writing then of business writing, which tends to be more terse and to-the-point.
Again, all this is leagues beyond what you need to know for the GMAT.

The upshot is that (C) is perfect, elegant, and 100% grammatically correct--this certainly could be correct on the GRE, for example. Again, it is a fancy academic way of conveying the information. Conceivably it might be a correct GMAT SC answer on its own. It's only problem is that it is wordy, baggy, and indirect, so it looks sick by comparison with (A). Whereas (C) is fancy and highfalutin, (A) is direct, terse, and clear--much more in line with the GMAT's standards. There is no doubt that (A) is the best answer of the five.

Does all this make sense?
Mike
_________________

Dear Mike,
Thanks for help and support as usual

Actually I hoped you can shed some light on the following grammar construction in choice C:

In less than..........since African honeybees had been released................ had migrated

As far as I learned, what comes after 'since' is 'Past simple' or 'certain points such as: month, year..etc' NOT 'past prefect', especially that the main clause of the sentence has 'past prefect'.

Can you help clarify please??