In the Centerville Botanical Gardens, all tulip trees are older than

Question

In the Centerville Botanical Gardens, all tulip trees are older than any maples. A majority, but not all, of the garden's sycamores are older than any of its maples. All the garden's maples are older than any of its dogwoods.

If the statements above are true, which one of the following must also be true of trees in the Centerville Botanical Gardens?

(A) Some dogwoods are as old as the youngest tulip trees. 
(B) Some dogwoods are as old as the youngest sycamores. 
(C) Some sycamores are not as old as the oldest dogwoods. 
(D) Some tulip trees are not as old as the oldest sycamores. 
(E) Some sycamores are not as old as the youngest tulip trees.

CrackverbalGMAT · Answer

The right answer here is  E . Inference questions can sometimes be tricky since you have to pick an answer that is true 100% rather than something that is just 'mostly true'. However, the best way to do this is to instead eliminate answers that have even the slightest potential to be false. This means that you're eliminating based on "can be false". When you have 'some/sometimes' statements, the best way to do this is to put a 'not' before the some/sometimes and see if its possible that it can be true.

We know: All tulips older than maples, All maples older than dogwoods, most Sycamores older than Maples but we don't know about the oldest Sycamores in relationship to tulips, or the youngest in relationship to dogwoods.

A  - Dogwoods are all younger than any of the tulips, so this is definitely false.  OUT

B  - Anything is possible with the Sycamores, and some dogwoods could be as old as the youngest ones. But, it's also just as likely that they may not be, so this can be false.  OUT

C  - Again, anything is possibly with the sycamores. It could be that some of them are younger than the oldest dogwoods, but it could just as easily be not.  OUT

D  - Once again, it is possible that the all the tulips are older than the oldest Sycamores, so we must eliminate because it can be false.  OUT

E  - It's simply not possibly that no sycamores are younger than the youngest tulips, since we know that some of them are younger than maples, and ALL maples are younger than the youngest tulip. Hence, this answer MUST be true.

- Matoo

kavach · Answer

In the Centerville Botanical Gardens, all tulip trees are older than any maples. A majority, but not all, of the gardenâ€™s sycamores are older than any of its maples. All the gardenâ€™s maples are older than any of its dogwoods.

If the statements above are true, which one of the following must also be true of trees in the Centerville Botanical Gardens?

(A) Some dogwoods are as old as the youngest tulip trees. 
Out as Maples are older than dogwoods.

(B) Some dogwoods are as old as the youngest sycamores. 
Out as sycamores are older than Maples.

(C) Some sycamores are not as old as the oldest dogwoods. 
Out as sycamores are older than Maples.

(D) Some tulip trees are not as old as the oldest sycamores. 
Out as no information is given.

(E) Some sycamores are not as old as the youngest tulip trees
Yes, this choice is true.

E

hovhannesmkrtchyan · Answer

I can't understand how is the right answer E.

A) This statement is clearly false since there is no overlap between tulip and dogwoods.
So, choice A is out.

B) We know that there are some sycamores that are younger than maples, and all dogwoods are younger than maples. It makes this answer choice ''can be true'', not ''must be true'', since it can be that some sycamores are younger than maples but older than dogwoods. But it can also be the case where some dogwoods are at least as old as some sycamores.
So, choice B is also out.

C) We know that majority of sycamores are older than maples, and all maples are older than any dogwoods. So, the statement that there are some sycamores that are not as old as oldest dogwoods has to be correct.

D) Along the same line of reasoning of choice B, this statement is also ''can be true'' statement. 
So, choice D is out.

E) We know that majority of sycamores are older than maples, and all tulips are older than maples. So, it can perfectly be the case that some sycamores that are older than maples can be as old as, or older than, tulips. There is an overlap between the two. How can we be sure that this statement is must be true, as opposed to choice C, which is always true regardless of the circumstances ? That's why I think that choice E is also ''can be true'' statement, and choice C is the correct answer here.

Please correct my reasoning if I am missing something crucial here.

MBAB123 · Answer

Well for C, you haven't considered the minority of sycamores. These minorities could be anywhere. They just have to be younger than 1 maple. That's all we can conclude about the minority of Sycamores and thus, some of them could be as old as the oldest dogwoods.

Option E is correct for similar reasoning. There are definitely some sycamores (minority) that are younger than at least 1 maple. As all the Tulips are older than all the Maples, some sycamores will definitely be younger than the youngest tulips. What you've stated about E (highlighted) is correct, but it has nothing to do with option E. What you've mentioned does not disprove E.

VerbalBot · Answer

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In the Centerville Botanical Gardens, all tulip trees are older than

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