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

00:00

A

B

C

D

E

Difficulty:

35% (medium)

Question Stats:

58% (01:27) correct
42% (00:39) wrong based on 43 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

Hey, Last week I started a few new things in my life. That includes shifting from daily targets to weekly targets, 45 minutes of exercise including 15 minutes of yoga, making...

This week went in reviewing all the topics that I have covered in my previous study session. I reviewed all the notes that I have made and started reviewing the Quant...

I started running as a cross country team member since highshcool and what’s really awesome about running is that...you never get bored of it! I participated in...