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 350,000 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:

If A, then B. If B, then C. If C, then D. If all of the [#permalink]
17 Aug 2011, 03:45

1

This post was BOOKMARKED

00:00

A

B

C

D

E

Difficulty:

35% (medium)

Question Stats:

51% (01:24) correct
49% (00:48) wrong based on 73 sessions

If A, then B. If B, then C. If C, then D. If all of the statements above are true, which of the following must also be true? (A) If D, then A. (B) If not B, then not C. (C) If not D, then not A. (D) If D, then E. (E) If not A, then not D.

there are rules that concern negative and positive IF X THEN Y IF NOT X THEN NOT Y ETC..: if A then B means that if B did not happen than A did not happen. so: IF D not then C not. if C not then B not. if B not then A not. so if D not then not C,B or A.

If A, then B. If B, then C. If C, then D. If all of the statements above are true, which of the following must also be true? (A) If D, then A. (B) If not B, then not C. (C) If not D, then not A. (D) If D, then E. (E) If not A, then not D.

I saw the OA in the mail but C does make sense.

(A) If D, then A A will definitely result in D doesn't mean someone else can't trigger D. Maybe Z can spawn D. So, we can have D by Z. A is nowhere in the picture.

(B) If not B, then not C. Same logic as before. C is triggered by B doesn't mean ONLY B can trigger C. GHOST may trigger C. So, we have GHOST and C., and no B. This becomes false.

(C) If not D, then not A. Definitely true. If we don't see D, it means there CAN't be A. Know this. As soon as A appears, at least B,C,D also appear. Thus, if don't see D, there can't be any A. However, if we see D, there is no guarantee that A is there. CORRECT.

(D) If D, then E. What is E.

(E)If not A, then not D. As I said in option "C", D can be spawned by something else. Say GHOST->C->D Not true.

ok here's a simpler way, if you are good with quant inequalities

if A -- > B, if B -- C , If C -- >

which implies if A -- > D

if you negate, then it becomes the opposite ~D -- > ~A which is C

well i love the Qyant approach: did you mean to say something like:

IF (POSITIVE) A>B>C>D THEN THE IF NOT (NEGATIVE) WILL BE LIKE MULTIPLYING BY -(1) WHICH REVERSES THE INEQUALITY TO IF NOT D>NOT C> NOT B> NOT A

yup thats pretty much what i intend to say !!!

if A> B> C > D then negating/ NOT-ing the components simply changes the direction of the sign -A < -B < -C < -D (or -D> -C > -B > -A whichever way you are comfortable reading the equation from )

good question. i have an even better trick for such questions. i solved the question in 1:17; i could've done that even earlier. here's the trick.

a->b

to find what else can be true, reverse the order of a,b and make them logical negations of themselves.

a->b= b'->a' "if A, then B" = "if not B, then not A"

e.g. if it is cloudy, it will rain. if it is not cloudy, then it will not rain (incorrect. we're not sure) if it is raining, then it is cloudy (incorrect. again may be it also rains when there are no clouds. we don't know)

if it is not raining, then it is not cloudy (bingo! correct ans) _________________

If A, then B. If B, then C. If C, then D. If all of the statements above are true, which of the following must also be true? (A) If D, then A.If D, that means A already happened. Not the other way (B) If not B, then not C.If B, then C. If not B, we have no idea about C or D except A. (C) If not D, then not A.True. If not D, then not C, not B and not A. (D) If D, then E.Irrelevant. E is not in the question (E) If not A, then not D.If not A, we have no idea about B, C or E

Re: If A, then B. If B, then C. If C, then D. If all of the [#permalink]
30 May 2015, 21:02

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: If A, then B. If B, then C. If C, then D. If all of the [#permalink]
01 Jun 2015, 23:11

C D or for that matter any other resulting one (B,C,D) can exist without the cause also bc the argument only says that if A, B,C exists then will B,C,D exist respectively. reverse is not true there can be other causes too leading to the result. Thus we can say that no result means no cause ---- right and not that no cause means no result as result might exist bc of other causes too _________________

Apoorv

Plz Kusdos if you liked the post

gmatclubot

Re: If A, then B. If B, then C. If C, then D. If all of the
[#permalink]
01 Jun 2015, 23:11

Originally posted on MIT Sloan School of Management : We are busy putting the final touches on our application. We plan to have it go live by July 15...