Hi manhhiep2509,

With the example that you listed: "A and B are of no less importance to C"....

I have to ask about the "intent" of this sentence because it's not clear. Here are some examples of what you MIGHT be trying to say:

"A and B are no less important than C"

"A and B are no less important to C than D"

"A is no less important than B to C"

"A is no less important to C than B"

Each of these examples uses the comparison word "than" and follows Comparison/Parallelism rules.

GMAT assassins aren't born, they're made,
Rich

Hi manhhiep2509,

Now that you've provided the entire quote, I can tell you what this grammar rule is modeled on.

Normally, a comparison uses the word "than" and follows parallelism rules:

eg. This team score more points than that team.

The example that you provided is an alternative, but is more in line with the phrase "as....as." Here we're told that 3 things (cost of concrete/steel, time to fabricate, distance of project site to production site) are essentially of equal importance. This idea can be communicated in a number of ways. The one that's written here is sophisticated, but grammatically correct.

Another way to write it would be: "The time needed to fabricate the elements and the distance of the project from the production site are each as important as the relative costs of concrete and steel....."

Ultimately, there's nothing grammatically incorrect about the given sentence. It's a rarer style than typical, mid-level GMAT prompts, but it is "fair game" on the GMAT. Since the Test will adapt to you, if you're doing well, then you can expect to see more higher-level content (including style/wording of the prompt, the logic behind a question, types of questions, grammar tested, etc.).

GMAT assassins aren't born, they're made,
Rich

manhhiep2509 wrote:In manhattan sentence correction book the author says that "do not use a comparative adjective unless you have a than in the sentence". However, in some case I cannot find a way to correct a sentence using such adjective without than. For example:

A and B are of no less importance to C.

Please explain the use of comparison in this sentence.

Dear manhhiep2509,
I answered a question suspiciously like this on GC.

There, I noted --- there are all sorts of comparisons one can make without the word "than".
Compared to me, Einstein was much smarter.
In contrast to me, Kobe Bryant is taller.
Unlike Bach, Mozart wrote symphonies.
Italian cuisine is different from English cuisine in that the former uses more tomato sauce.

See this article on the idioms of comparison:
https://magoosh.com/gmat/2013/gmat-idioms-of-comparison/
Also, here's an idiom that involves a pair of comparative adjectives, and doesn't use "than" at all:
https://magoosh.com/gmat/2012/gmat-gramm ... mparisons/

Mike