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Definitely a difficult question, but it helped me to think of statement 1 in this way: "If you pick any two snakes, at least one is a viper". So, what if there are 4 snakes, 2 cobras and 2 vipers? Pick two snakes. You could get 1 cobra, 1 viper (which agrees with statement 1) Or you could get 2 vipers (also agrees with statement 1) Or you could get 2 cobras. This option DOES NOT agree with statement 1. So we know - that we cannot ever pick two cobras. The only way to ensure we never pick two cobras, given that there could be ANY NUMBER of snakes in the box, is if we only have ONE cobra. Ex: 4 snakes, 3 viper, one cobra. Pick two = 2 vipers, or 1 viper, 1 cobra.

I think this is a poor-quality question and the explanation isn't clear enough, please elaborate. GMAC say, they do not contradict the data given in 2 sentences in the DS problems. But here it contradicts. Can you please explain?

Where do you see a contradiction? The question is hard but perfectly fine.

I got this question right but I also thought there was a contradiction which made me second guess myself since official GMAC policy is DS stimulus will not contradict each other.

Per (1) there could only be two snakes in the box, one being a cobra, one being a viper. Thus (1) is sufficient.

(2) contradicts (1) in saying that there are 99 snakes in the box.

I think this is a poor-quality question and the explanation isn't clear enough, please elaborate. GMAC say, they do not contradict the data given in 2 sentences in the DS problems. But here it contradicts. Can you please explain?

Where do you see a contradiction? The question is hard but perfectly fine.

I got this question right but I also thought there was a contradiction which made me second guess myself since official GMAC policy is DS stimulus will not contradict each other.

Per (1) there could only be two snakes in the box, one being a cobra, one being a viper. Thus (1) is sufficient.

(2) contradicts (1) in saying that there are 99 snakes in the box.

The statements do NOT contradict each other:

The first statement implies that there must be exactly one cobra in the box. (2) says that there are 99 snakes. So, 1 cobra and 98 vipers.
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I thought this was a very challenging question that I got wrong, but after reading through everyone's explanations I now understand.

What most of (those who got it wrong) did was read over the original question, and then totally forget about it. There has to be @ least 1 cobra, and @ least one viper.

A lot of people on this forum are over-complicating things.

If you grab ANY TWO snakes, one or more has to be a viper. That is saying that it's IMPOSSIBLE to grab 2 cobras. So there is only 1 cobra as per the question stem.

Took me some time to get this, it's a good question. 1) FROM ANY 2 SNAKES AT LEAST 1 IS A VIPER. >>> This means that if I have one cobra and 1 Viper I have sufficiency. >>> What happens if I add a Cobra? So now have 2 Cobras and 1 Viper. Here it's where it gets tricky, because the question is not testing proportions, it's testing logical deduction. I have 2 cobras and 1 Viper now, if I decide to pull out 2 snakes from pandora, I can get 1 Viper and 1 Cobra OR 2 Cobras. If I get 2 Cobras I'm not only dead but I'm also not respecting the condition that AT LEAST ONE IS A VIPER.

I think this is a poor-quality question and I agree with explanation. The natural interpretation of "for every x of this there is y of this" is that there is a minimum ratio

I think this is a poor-quality question and I agree with explanation. The natural interpretation of "for every x of this there is y of this" is that there is a minimum ratio

Can you please elaborate what you mean?
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I think this is a high-quality question and I don't agree with the explanation. hi, the question tells us that there is 1 viper & 1 snakes per box. So, the question asks how many cobras are there. this means that the question is asking to find out the total no of cobras. Isn't it?

I think this is a high-quality question and I don't agree with the explanation. hi, the question tells us that there is 1 viper & 1 snakes per box. So, the question asks how many cobras are there. this means that the question is asking to find out the total no of cobras. Isn't it?

We need to know how many cobras are in the box. And the info given in (1) tells us that there must be exactly one cobra in the box.
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Try to think this way - Condition: four snakes in the box (V, V, C, C).

Scenario 1: I put my hands inside the box and pull out 1C and 1V, Stat 1 satisfied and so does condition in question stem. Scenario 2: I put my hands inside the box and pull out 1V and 1V, Stat 1 satisfies and so does condition in question stem. Scenario 3: I put my hands inside the box and pull out 1C and 1C, Is this scenario possible without violating Stat 1? NO. If we consider stat 1 as true, this scenario fails.

PS: Stat 1 means if we pull two snakes from the box, both can be V or atleast one SHOULD be V. Similarly, we can have "n" number of snakes inside the box. But, if we consider stat 1, we are bound to have only one cobra.

I think this is a poor-quality question and I don't agree with the explanation. Hi there, so for (1) in my opinion let us assume it is 2 snakes only in the box. it could be 1 cobra and 1 viper or 2 vipers and 0 cobras. two potential solutions. Or do you say because of the first sentence *there is atl east one viper and at least one cobra in the box* this tells us the other one must for sure be a cobra?

I think this is a poor-quality question and I don't agree with the explanation. Hi there, so for (1) in my opinion let us assume it is 2 snakes only in the box. it could be 1 cobra and 1 viper or 2 vipers and 0 cobras. two potential solutions. Or do you say because of the first sentence *there is atl east one viper and at least one cobra in the box* this tells us the other one must for sure be a cobra?

The question is correct. It's not just that easy.

As for your question: the stem clearly says in the first sentence "There is at least one viper and at least one cobra in Pandora's box". WHY do you consider the case which contradicts this???
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