LR Question 22 Explanation
QUESTION TEXT: No chordates are tracheophytes, and all members of…
QUESTION TYPE: Sufficient Assumption
CONCLUSION: P ➞ not H
REASONING: C ➞ T and P ➞ T. These can be joined to form P ➞ T ➞ C
ANALYSIS: This question is truly worth drawing. We have to get from P to not H. Notice that nothing is connected to H. So the only way we can get there is through T and C. Here’s what we have so far:
P ➞ T ➞ C ???? H
Just put an arrow in place of the question marks and we get our conclusion: P ➞ T ➞ C ➞ H
So the right answer has to be either “C ➞ H” or the contrapositive of that: “H ➞ C”
___________
- This doesn’t work. We can’t connect it up to our diagram to reach the conclusion. If no H were T, this would have worked.
- CORRECT. See the diagrams above.
- This doesn’t help us connect anything to H. The right answer will always have to mention the disconnected term.
- This tells us that if you are C then you are not H. That doesn’t help, because Ps are not Cs.
- This still leaves us without any connection to H.
More Resources for Sufficient Assumption Questions
- Conditional Reasoning Article: Learn about conditional statements.
- LR Diagrams Guide: Learn how to draw LR diagrams.
- Intro to Conditional Reasoning: Learn conditional reasoning basics.
- Intro Course lesson: This intro course lesson covers Sufficient Assumption questions.
- Mastery Seminar lesson: This LR Mastery seminar lesson covers sufficient assumption questions.
Hello,
I am trying to find the stimulus to many of the questions online, and that is proving rather difficult. Is this a copyright issue? The explanations are much appreciated, but it would be more helpful to have access to more questions.
Many Thanks
Hi Amira,
Yes, LSAT practice tests need to be purchased from LSAC, the makers of the test. They’re available in books of tests, or as individual tests. You can find more information about where and how to buy LSAT practice tests here: https://lsathacks.com/lsat-preptests/