Jim is going to a concert.

[GoldenGuppy]

Hey guys,

I'm working on this data sufficiency question for my GMATS, wondering if anybody can lend me an explaination.

"Jim is going to a concert. Is George going to the concert?"

(1) If George goes to a concert, then Jim will go to the concert

(2) If George does not go to a concert, then Jim will not go to the concert




(A) Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient
(B) Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient
(C) BOTH statements (1) and (2) TOGETHER are sufficient, but NEITHER statement ALONE is sufficient
(D) Each statement ALONE is sufficient
(E) Statements (1) and (2) TOGETHER are NOT sufficient

I chose (D), but the answer turns out to be (B), I am confused at the logic, it seems easy to grasp, I just need an explaination 🙂

Thanks!

 

[simms]

That's easy. Just because Geroge goes doesn't mean Jim goes.

But the thing is, B says that george doesn't go, then jim won't go. But you KNOW jim is going. 1 is just obsecure because Even if jim goes, no idea on if george will go or not.
to make sense, 1 should be

If jim goes to the concert, then george will go.

 

[HonkeyDonk]

B is correct.

Let's say you ONLY had statement (1).

Thus it tells you that if G goes, J goes. But it doesn't say what happens if G doesn't go...maybe J will still go, who knows, INSUFFICIENT

Let's say you ONLY had statement (2)

Thus it tells you that if G doesn't go, J doesn't go. So if J is going, then G has to be going as well. SUFFICIENT.

Then from there, u can eliminate the other possibilities.

 

[DaveSimmons]

"If A then B" is not reversible, so (1) doesn't tell you the truth of A

 

[oboeguy]

9th grade logic problem here. Converse is not always true so 1 is not enough. Contrapositive is always true, though, so 2 is enough. Look-up some of these rules of logic and you'll have a way easier time with these problems. Good luck, GG!

 

[CrackRabbit]

Better question, how many doobies will Jim and George smoke at the concert before picking up some skanky looking chicks and a bag of Doritos?

 

[TwiceOver]

B and I don't really understand the question.

 

[yakko]

Put them both on a skewer and roast them.

 

[dfi]

Well statement 1 is obviously insufficient. It doesn't say whether or not Jim will go if George does not go. Thus, insufficient data.

Statement 2 tells us that the only way for Jim to go to the concert, is if George is not NOT going to the concert. Or in other words, Jim will only go if George is going. This presents sufficient data to answer the question. Thus, the answer is (B).

Now, what I think is confusing you is the fact that statement 2 SEEMS insufficient. Your logic is probably along the lines of "Well, Jim won't to the concert if George is going. But couldn't Jim still refuse to go to the concert if George DOES go?" Yes, this is very true. Jim could refuse to go even if George goes to the concert. However, statement 2 tells us that Jim will NEVER go to the concert if George doesn't go. Jim only has the OPTION of going (whether or not he choses to go is another issue) if George goes. Thus statement 2 tells us that when Jim is allowed to exercise the option to go to the concert, it must be because George is also going.

Oh btw, I don't know if the GMAT has a written portion. But "explaination" is actually spelled "explanation". The "i" is superfluous.

dfi

 

[Kibbo]

Tell me you're taking the GMATS for history or something.