Common vs commonly

[prachich1987]

In contrast with cartographers' most common design of maps that only measure distance , contour maps also measure elevation or height below or above sea level.

A. cartographers' most common design of maps that only measure distance
B. cartographers and their most common design of maps that only measure distance
C. the most common maps designed by cartographers that only measure distance
D. the most commonly designed maps of cartographers that only measure distance
E. the most commonly used maps and only measuring distance

Source :Kaplan
OA : C
How to choose C over D

[jaymw]

This question tests parallelism.

In contrast with X, contour maps measure something.

You should always compare like things on the GMAT. Therefore, in this example, you must compare maps with maps, and not cartographers with maps or designs with maps. For precisely this reason, A and B are out.

In answer choice E, the word "and" causes confusion. Without it, "only measuring distance" would correctly modify "most commonly used maps". Apart from this, when comparing answer choice E to the original sentence, the entire part about the cartographers has been left out. This is a substantial change in meaning. Therefore, E cannot be correct.

In D, "maps of cartographers" is awkward. You can't have a map of a person, but only one of a city or country or the like.

So, we are left with C. Here, we are comparing maps with maps and encounter no further grammatical trouble.

Hence, C is the correct answer.

[prachich1987]

This question tests parallelism.

In contrast with X, contour maps measure something.

You should always compare like things on the GMAT. Therefore, in this example, you must compare maps with maps, and not cartographers with maps or designs with maps. For precisely this reason, A and B are out.

In answer choice E, the word "and" causes confusion. Without it, "only measuring distance" would correctly modify "most commonly used maps". Apart from this, when comparing answer choice E to the original sentence, the entire part about the cartographers has been left out. This is a substantial change in meaning. Therefore, E cannot be correct.

In D, "maps of cartographers" is awkward. You can't have a map of a person, but only one of a city or country or the like.

So, we are left with C. Here, we are comparing maps with maps and encounter no further grammatical trouble.

Hence, C is the correct answer.

thanks for the above nice explanation
Now from below two which one will you choose and why?

the most common maps designed by cartographers that only measure distance
the most commonly designed maps by cartographers that only measure distance

[jaymw]

I can't give you a really academic reason for my choice, but I'd definitely go with the first option.

In the second option, the piece "by cartographers" seems out of place!

But then again, I really don't think the differentiation between "common" and "commonly" is the main issue here. Common, as an adjective, correctly refers to maps, whereas commonly, as an adverb, correctly refers to the verb "designed".

[gmat1011]

in your modified sentence:

the most common maps designed by cartographers that only measure distance
the most commonly designed maps by cartographers that only measure distance

"commonly designed maps by" is not correct

'commonly designed' describes the maps. it describes the attributes of the maps in the same way as an adjective would. "designed" here is not functioning as a verb.

In this passive construction you are trying to connect the agent who did an action ('designing') with the actual actionl..

... maps... designed BY cartograhers... is correct

[RACHVIK]

Lets look at two options more closely.

the most common maps designed by cartographers that only measure distance
the most commonly designed maps by cartographers that only measure distance

compare these with the original sentence. As per the sentence, emphasis is on design of maps and not on how maps are designed. hence option C is correct.

thanx

[AIM GMAT]

Be carefull when "ly" appears , commonly is adverb and common is adjective.

C. the most common maps designed by cartographers that only measure distance
---- Here meaning says we need maps which are common and designed by cartographers.

D. the most commonly designed maps of cartographers that only measure distance
---- Here meaning says most frequently designed maps of cartogarphers .

Now which is the better meaningful sentence ? [Dnt get biased by colours]

Hope this helps.

[Jim@Grockit]

I'd also say that the phrase "that only measure distance" is a problem -- in D, it sounds like it is the cartographers that only measure distance, rather than the maps, as restrictive phrases with "that" default to modifying the noun right before them.

[KapTeacherEli]

(D) can also be ruled out due to a preposition error; "commonly designed maps of cartographers" implies that the maps either belong to, or are made of, cartographers; (C)'s "designed by cartographers" is correct.

Hope this helps!

[cgoyal.gmat]

Hello,
In option "c" (the most common maps designed by cartographers that only measure distance), it appears to me that it is the 'cartographers' that only measure the distance, not the maps.
If option "d" has an issue with "that only measure distance", then even option "C" has the same issue.
Or do I not understand the modifier 'that' correctly?
Thanks!

[KapTeacherEli]

Cartographers are people. A phrase meant to describe people would be connected to the sentence with the word "who," rather than the word "that"

It's stylistically awkward, but unambiguously clear, that the word "maps" is being modified twice, by both "designed by cartographers" and "that only measure distance"

[dodgeforgmat]

In option D'.....maps of Cartographers...' is the clear deterent. It brings out a meaning that the Cartographers are the once who are mapped, which is incorrect.

Even if option D were to state '.....maps by cartographers..', I would opt for C, albite for a less obvious reason. The emphasis of the sentence is on 'maps' and not on 'design'. The contrast, drawn in the sentence, is b/w Comman maps by cartographers and Contour maps. A simple way of arriving at the answer choice is to eliminate the word 'designed' from the answer choice and check if the contrast hold good. Repeat the process after eliminating 'maps'. Clearly, eliminating 'maps' would mean that we are comparing 'design' to 'maps' which is incorrect.

[navami]

Thanks Jim ... Great Explaination

[aspirant2011]

I don't think so this question tests the common vs commonly issue because it tests about the comparison issue between common maps and contour maps

D talks about design of common maps and is therefore the wrong comparison

[iamadiga]

I'd also say that the phrase "that only measure distance" is a problem -- in D, it sounds like it is the cartographers that only measure distance, rather than the maps, as restrictive phrases with "that" default to modifying the noun right before them.

I thought that refers to "cartographers" and hence eliminated the choice. Can someone help me with the usage of "that". Should i take the reference of nounc which is not part of the preposition always ?