Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Augustus DeMorgan made many valuable contributions to [#permalink]

Show Tags

21 Sep 2012, 23:40

10

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

45% (medium)

Question Stats:

51% (01:51) correct
49% (00:55) wrong based on 290 sessions

HideShow timer Statistics

Augustus DeMorgan made many valuable contributions to calculus, trigonometry, algebra, and logic; but perhaps his most famous academic contribution, a pair of theorems concerning complementation of sets, is still known today as DeMorgan’s Rules.

a.a pair of theorems concerning complementation of sets, is

b.a pair of theorems concerning complementation of sets, are

c.two theorems that have to do with complementation of sets, are

d.two theorems that define complementation of sets, is

e.two theorems that are both related to complementation of sets, are

Re: Augustus DeMorgan made many valuable contributions [#permalink]

Show Tags

22 Sep 2012, 05:17

7

This post received KUDOS

Expert's post

1

This post was BOOKMARKED

The subject ‘contribution’ plays a key role in deciding the answer here. First being a singular subject, the subject’s verb also should be singular –i.e.: is, dismissing B, C and E. Second, the singular subject entails a singular appositive modifier, namely, a pair as in A and not two theorems as in D. Hence A . _________________

“Better than a thousand days of diligent study is one day with a great teacher” – a Japanese proverb. 9884544509

Re: Augustus DeMorgan made many valuable contributions [#permalink]

Show Tags

23 Sep 2012, 08:47

I chose A for the following reasons: 1. the Qn has non-essential modifier marked with ",". Thus we can disregard it. Subject contribution, verb is known as contribution is singular. Options A and D left; 2. Verb define in option D changes the meaning the sentence - we don't know for sure, whether they defined or concerned complementation of sets. Option A left.

Re: Augustus DeMorgan made many valuable contributions to [#permalink]

Show Tags

26 Aug 2014, 15:38

Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.

Re: Augustus DeMorgan made many valuable contributions to [#permalink]

Show Tags

27 Aug 2014, 21:36

daagh wrote:

The subject ‘contribution’ plays a key role in deciding the answer here. First being a singular subject, the subject’s verb also should be singular –i.e.: is, dismissing B, C and E. Second, the singular subject entails a singular appositive modifier, namely, a pair as in A and not two theorems as in D. Hence A .

I am confused with choosing A or D. It helps me answer my question. Thank your for exp. +1 kudos _________________

......................................................................... +1 Kudos please, if you like my post

Re: Augustus DeMorgan made many valuable contributions to [#permalink]

Show Tags

01 Sep 2015, 03:21

Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.

Re: Augustus DeMorgan made many valuable contributions to [#permalink]

Show Tags

07 Sep 2015, 10:30

Augustus DeMorgan made many valuable contributions to calculus, trigonometry, algebra, and logic; but perhaps his most famous academic contribution, a pair of theorems concerning complementation of sets, is still known today as DeMorgan’s Rules.

his most famous academic contribution-------> Contribution referes to Singular Object...

So the decision point isIS / ARE

The correct answer will include IS , Only OPtions (A) and (D) are available...

(D) two theorems that define complementation of sets, is ----> Two theorems............must be are

(A) a pair of theorems concerning complementation of sets, is -----> A pair of ........ is (Correct)

Hence (A) is the best choice... _________________

“Give me some sunshine Give me some rain Give me another chance I wanna grow up once again.”

Augustus DeMorgan made many valuable contributions to [#permalink]

Show Tags

05 Mar 2016, 11:59

Expert's post

Quote:

Augustus DeMorgan made many valuable contributions to calculus, trigonometry, algebra, and logic; but perhaps his most famous academic contribution, a pair of theorems concerning complementation of sets, is still known today as DeMorgan’s Rules.

a.a pair of theorems concerning complementation of sets, is

b.a pair of theorems concerning complementation of sets, are

c.two theorems that have to do with complementation of sets, are

d.two theorems that define complementation of sets, is

e.two theorems that are both related to complementation of sets, are

Subject-verb combination quickly eliminated B, C and E due to plural verb are.

Coming to A and D, both are different in meaning.

Quote:

Concern means Relate to; the story concerns a friend of mine (be concerned with) this fable is concerned with forgiveness and redemption

MORE EXAMPLE SENTENCES Of course, the Today Tonight story was only concerned with the latter issue. Julian Barnes's new book of short stories is concerned with old age and death.

a pair of theorems related to complementation of sets is not the same as two theorems that define complementation of sets since we do not know whether theorems are just related to the complementation of sets or they define complementation of sets. We cannot assume so go for A. _________________

The only time you can lose is when you give up. Try hard and you will suceed. Thanks = Kudos. Kudos are appreciated

Re: Augustus DeMorgan made many valuable contributions to [#permalink]

Show Tags

05 Mar 2016, 12:40

subject ‘contribution’ plays a key role in deciding the answer here. First being a singular subject, the subject’s verb also should be singular –i.e.: is, dismissing B, C and E.

answer A . _________________

Please press 1 kudos if you like my post .Thanks

gmatclubot

Re: Augustus DeMorgan made many valuable contributions to
[#permalink]
05 Mar 2016, 12:40

Last year when I attended a session of Chicago’s Booth Live , I felt pretty out of place. I was surrounded by professionals from all over the world from major...

I recently returned from attending the London Business School Admits Weekend held last week. Let me just say upfront - for those who are planning to apply for the...