Fred has greater lung capacity than George. Since Harold has greater

Question

Fred has greater lung capacity than George. Since Harold has greater lung capacity than Joe, it follows that Fred must have greater lung capacity than Joe.

Any of the following, if introduced into the argument as an additional premise, makes the argument logically correct EXCEPT:

A. Fred has greater lung capacity than Harold.

B. George has greater lung capacity than Harold.

C. Fred and Harold have the same lung capacity.

D. Harold has greater lung capacity than George.

E. George and Harold have the same lung capacity.

skipjames · Accepted Answer

Now I know there is some symbolic logic method which I learned years ago in college, but I don't remember anymore. Still it is simple. Pretend they are numbers. F>G, H>J, which additional statement makes F>J?
F>H, G>H, F=H, H>G, G=H. So if anything is greater than or equal to H it will be greater than J. That is exactly what the first three statements and the last say. The fourth statement leaves us hanging. Knowing that harold is greater than george does not tell us about the relationship between george and joe, let alone fred and joe.

So statement D. is the exception.

If these comments were helpful to you, please give kudos.
Thanks,
Skip

nverma · Answer

Let's use some maths here..
Let the respective capacities of Fred,George, Harold, Joe be F,G,H and J

Given: F > G, and H > J 
To prove : F > J
As per the argument we have 4 options, which can prove F > J.

Option 1:
F > H, but given: H > J , so F > J

Option 2:
G > H, but given F > G and H > J ...So F > G and G > H and H > J....so F > J

Option 3:
F = H, but given H > J...So F > J

Option 4:  ANSWER 
H > G... But we don't know what is the relation of H and F... So We CAN'T prove that F > J

Option 5:
G = H, but given that F > G, so F > H, but H > J...so F > J

Hope it helps..revert if not clear

perseverant · Answer

Thanks to both of you, it is clear how I should proceed, now I just need to keep practive this kind of question an get it done in less than 2 mins.

mkdir · Answer

Given:
1. F > G
2. H > J
3. F > J

Answer evaluation:
A. F > H ; F > H > J. Therefore, F > J
B. G>H; F>G>H>J. Therefore, F>J
C. F=H; F = H>J. Therefore, F>J
D. H>G; if H = 10, G=5, J = 8, F = 7, then F !> J - CORRECT ANSWER
E. G = H; F > G = H > J. Therefore, F > J

Sent from my Redmi Note 5 Pro using  GMAT Club Forum mobile app

VerbalBot · Answer

Automated notice from GMAT Club VerbalBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

Fred has greater lung capacity than George. Since Harold has greater

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Critical Reasoning (CR) Questions

Fred has greater lung capacity than George. Since Harold has greater

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards