A park contains at most five of seven kinds of trees - firs, laurels

Question

A park contains at most five of seven kinds of trees - firs, laurels, maples, oaks, pines, spruces, and yews - consistent with the following conditions:

If maples are in the park, yews are not.

If firs are in the park, pines are not.

If yews are not in the park, then either laurels or oaks, but not both are in the park.

If it is not the case that the park contains both laurels and oaks, then it contains firs and spruces.

Which one of the following could be a complete and accurate list of the kinds of trees in the park?

(A) firs, maples

(B) firs, laurels, oaks

(C) firs, laurels, pines, spruces

(D) firs, laurels, spruces, yews

(E) firs, maples, oaks, spruces, yews

VeeB · Answer

Answer (D)

I went with the elimination process and ended with D, however by doing so I took close to 3 minutes. This is a pretty new format of logic. Do we have a smarter strategy? Maybe a sketch or diagram could help. Looking for ideas.

Posted from my mobile device

Akkiiii · Answer

how did you guys eliminate A?

VeeB · Answer

Because if Maples are in the park Yews aren’t, per condition 1. And, since Yews are NOT in the park then either Laurels or Oaks NEED to be in the park, per condition 3.
Therefore, Option A can be eliminated, as it isn’t representative of the accurate list of trees.

Posted from my mobile device

unraveled · Answer

A park contains at most five of seven kinds of trees - firs, laurels, maples, oaks, pines, spruces, and yews - consistent with the following conditions:

If maples are in the park, yews are not.

If firs are in the park, pines are not.

If yews are not in the park, then either laurels or oaks, but not both are in the park.

If it is not the case that the park contains both laurels and oaks, then it contains firs and spruces.

Which one of the following could be a  complete and accurate list  of the kinds of trees in the park?

(A) firs, maples

(B) firs,  laurels, oaks

(C)  firs , laurels,  pines , spruces

(D) firs, laurels, spruces, yews

(E) firs,  maples , oaks, spruces,  yews

From passage:
M ----> nY ----> L/O ----> F(F ----> nP) and S

A and D stand out but here A does not cover the other trees, hence out.

Answer D.

Purnank · Answer

agree with your explanation but what about yews.
I dont understand how it fits there?

yazadsarkari · Answer

A shouldn’t be an option here I think the answer A should be modified as there is no way to eliminate both A and D

LamboWalker · Answer

A is not the right answer.

'If yews are not in the park, then either laurels or oaks, but not both are in the park.'

There are no yews in option A, but neither are there laurels or oaks. Therefore, A can be eliminated.

unraveled · Answer

If maples are in the park, yews are not.
If firs are in the park, pines are not.
If yews are not in the park, then either laurels or oaks, but not both are in the park.
If it is not the case that the park contains both laurels and oaks, then it contains firs and spruces.

In the above condition the 4th one makes sense.
Now either L or O is there, we can take either. Given the option L is there so we take it.
Further what might be possible? 
Neither 1st nor 2nd condition is fulfilled becasue if both L and O are not there then Y is there and hence M is not in the park. 
Understand the 3rd condition well to crack this one.

It means that Y can be there if O is there.
Y can be there if L is there.
Y is not there if both L and O are not there.

Note: It is bit confusing for me since contradiction did arise for me. There are many versions of this question and in all of them the confusion remains. I chose to go with D because it made more sense POE-wise.

HTHs.

RenB · Answer

Hi  KarishmaB 
What would be the contrapositive of 'If yews are not in the park, then either laurels or oaks, but not both are in the park'?
While I read the conditions, I simultaneously write the contrapositives to get more clarity on the possibilities. I rephrased this statement to-
If both L and O ----> Y
Or If not the case that case only L nor only O ----> Y
This doesnt fit with D :/
Look forward to your explanation

KarishmaB · Answer

'If yews are not in the park, then either laurels or oaks, but not both are in the park' If A, then B A - yews are not in the park B - either laurels or oaks, but not both are in the park Negated A - yews are in the park Negated B - Either both laurels and oaks or neither is in the park Here, A implies B and B' implies A' So the following are implied: If yews are not in the park, then either laurels or oaks, but not both are in the park. If either both laurels and oaks are in the park or neither is in the park, then yews are in the park. The following are not implied: B does not imly anything A' does not imply anything If either laurels or oaks, but not both are in the park, then nothing about yews is implied. Yews may be may not be in the park. If yews are in the park, then nothing about laurels and oaks are implied. They may be, may not be, both may be, both may not be in the park. Conditionals: https://youtu.be/MmlwcTlHZz8

A park contains at most five of seven kinds of trees - firs, laurels

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

­A park contains at most five of seven kinds of trees - firs, laurels

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

A park contains at most five of seven kinds of trees - firs, laurels