June 2013 LSAT, LR1, Q10 Eocene and nahcolite

Crowdsourcing the June 2013 LSAT:  June 2013 LSAT Explanation Central | About this project Scott Cowan is the kind of guy who brings eight random friends to a tour of Anchor Brewing Company at eleven a.m. on a Tuesday. (San Francisco is the kind of place where eight random friends say “sounds great” to beers at eleven a.m. on a Tuesday.) Scott's also the kind of guy who makes you waffles from scratch when you're at a business meeting at his house. When he's not enthusiastically traveling the world, or writing 5,000-word emails, he is an exceptionally fun and empathetic teacher.

Guest blogger: Scott Cowan

To answer this question, I used three classic techniques honed over 30 years of working with logic/reading questions. These “Logical Weapons of Mass Deduction” work without fail for tests including the ACT, AP exams, GRE, HSPT, LSAT, SAT, and SSAT [”˜without fail' for students who practice the techniques!]:

1) Mark Key Terms (MKT); 2) Evidence in Text (ET); and 3) Process of Elimination (POE).

I often use these acronyms as verbs and nouns”¦ and sometimes even sling them whilly-nilly in all directions as other parts of speech. It's not grammatical, but it does help students remember to use the techniques consistently, confidently -- and ruthlessly! -- to get high scores. These three techniques combine to form a dynamic, logical-reasoning trio that vanquishes foes from the flimsy to the fierce so that you need never fear any question.

1a) First, let's use MKT to figure out what, precisely, is asked in the question, and then, what is presented in each Answer Choice (AC).

It's important to remember that each answer choice which contains even one wrong word is entirely wrong. There is only one answer choice that is 100% correct. Four answers contain at least one minor flaw.

At first, I Marked (underlined or jotted down in the margin) the Key Terms of the Question:

“salty lakes;” “*52-50 million years ago (MYA);” “nahcolite**;” “Eocene;” “formed ONLY when atmosphere = 1,125 ppm CO2 or greater”

1b) I next examined the precise Question. This is a part of the test that way too many test-takers hurry through. Haste really does make waste on tests. It's a waste of your precious time to choose a wrong answer when a few seconds of careful scrutiny of the Question would lead you to the right answer and a higher score! Slow Down and Get As Many Questions Right As You Can to reach your highest possible score.

My MKT for the precise Question:

“Most Strongly Support” (editor's note: This means the LSAC calls this one a Must Be True question. --nathan)

Thus armed with my MKT weapons, I boldly strode through the choices, ready to slay any wrong part of any answer. The battle was swift and all foes fell quickly in the face of my MKT sword. I wielded this sword, sharpened on ET culled from the question and the passage to POE unsupported AC.

2) My ET is contained in the MKT of this tiny passage. (See above.) For longer passages, I might have to re-read important sections to ensure I found clear Evidence for both right and wrong answers).

3) POE: As we examine each AC, we will use POE to eliminate the precise wrong word or phrase that invalidates that particular Choice.

One at a time, let's cross out the wrong bits in 4 answers, and see how we're left with only one answer that is “most strongly supported.”

Ah, a short note about syllogisms before we start. Remember that we're asked to choose the answer that is supported by the statements above. We are, thus, being asked to use a particular kind of deductive reasoning called a syllogism, in which we're given a set of facts (”˜givens') and asked to reason out a 100% airtight truth from just these facts. Do not stray beyond the ”˜givens' in the statements provided”¦ even if you know more about nahcolite or wrote your PhD dissertation on “Salty lakes of the Eocene,” you must stay within the bounds of the ET – only the Evidence presented in this one passage.

A: I noticed the word “most” twice in this AC.  Nice trick, LSAT!  “Most” is enticing. It's certainly more likely right than more absolute terms such as “always” or “never” but not as likely as less absolute terms such as “sometimes.” These thoughts stay mainly in the background, though, as I ruthlessly wade through the AC and slash my pencil through wrong words. It turns out, in fact, that “most” is a silly word here. (slash) Do the given facts prove that “'most' of the time” CO2 levels were lower after the Eocene than during it? “A” says nothing about 52-50MYA CO-2 levels. If CO2 levels were 1340ppm during the Eocene and 1300ppm after the Eocene, CO2 levels would still be higher during the Eocene than after, but always high enough to support the formation of nahcolite. If CO2 levels during the Eocene were only 1,124ppm and then never reached above 1,123ppm afterwards,  all the words in "A," no matter how true, could combine to support the statements posed in question 10. The Eocene could've lasted longer than the 2MY between 52-50MYA*; ***, which makes "A" unknown even within the epoch itself. Thus, AC ”˜A' is as wrong for us as was that person we met at cousin Phyllis' wedding in Altuna who looked so good at 3am when the band had packed it in and nearly everyone else had gone home”¦ but didn't seem quite so exciting when we returned home and reassessed our options.

B: “Oy Vey,”  I hear my Yiddishe grandmother complaining about her neighbor who wasted her time with useless bits of non sequiturs – time she could've put to good use beating her friends at mahjong and earning dimes and nickels for my college fund.  Again, we have no idea whether CO2 levels ever rose above 1125ppm or not during the period of the Eocene that spanned 52-50MYA”¦ Waste not even two seconds on this silly ”˜distractor.'  What in the world does this “fluctuating” have to do with anything? POE it with your sword”¦errr, pencil. Knowing only that levels “fluctuated” (slash) is worth as much as is war according to the 1970 lyric from Edwin Starr's famous song: “absolutely nothing.”

C: Here's a classic example of mixing/matching key terms from the passage in random ways. Do not be fooled!  There's no causation/correlation indicated in the passage and none asked in the question about the precise point made in answer "C": “when/where/whether lakes are salty at different atmospheric concentrations of CO2.” This one tries to mystify readers who rush too fast to think clearly, and then choose a complex-looking answer that contains important terms from the passage... in ways that stray off-topic. It's another classic ”˜distractor.'  "C" tells us that lakes are more likely salty when atmospheric levels of CO2 stray above 1125 ppm, but we're not told whether lakes were salty 52-50MYA, during the Eocene. This is a ”˜silly-gism' that gives unrelated bits of information and posits an unrelated pseudo-conclusion; it is not a ”˜syllogism' that uses facts from the given statements in Question 10 and then reasons out an ineluctable truth from them. There's no one word to eliminate, but we can destroy answer ”˜C' mercilessly because its parts do not form a coherent whole. Then we move on confidently, pencil poised to do more damage.

D: Ah! This is not a flashy choice”¦ not like that ”˜A' that winked at us with those big “most” eyes and not like ”˜C' which waved those saucy, alluring terms all over the place, flaunting ”˜Eocene epoch' and flashing “ppm of CO2.” No, "D" is a more subtle choice that just might fit our precise needs. Let's take it one step at a time and rationally, not rashly, make an informed decision. When we MKT ”˜D,' we see “atmosphere = ”˜at least' 1,125ppm CO2;” “for ”˜at least' ”˜some' of the Eocene.” Simple syllogistic logic shows us that ”˜D' must be true:

given that: a) nahcolite forms in salty water only when atmospheric CO2 levels reach/exceed 1125ppm and b) nahcolite was found in salty lakes from the Eocene period then: c) there must have been “at least 1,125 ppm CO2 during at least some parts of the Eocene epoch.”

So, ”˜D' is a bit stiff, and way too conservative for us to hang with after we're done with question 10, but it's entirely dependable for this one question. It's not going to make us look stupid: It completely satisfies all parts of the question asked and is fully supported by ET we MKT'd earlier. We cannot POE it, b/c it's the right answer.

E: Another distractor hoping to waylay an naive bystander.  You're probably not this naive; you're certainly no bystander. You're a thoughtful LSAT-taker armed with “logical weapons of mass deduction”: MKT, ET, and POE! You calmly march your pencil, word by word, through AC ”˜E' and slash out the word “since.” Who cares what happened ”˜since' the Eocene?!?  This has nothing to do with the question asked. Knowing that little nahcolite formed after the Eocene does not help us determine anything about nahcolite during the Eocene, does it?

You reasonably ask, “Why bother checking 'E' if we figured out the right answer was ”˜D'?”  My equally reasonable answer:  No one is perfect. POEing through all five answers provides us a way to double check we've not made any mistakes. If we find two seemingly right answers, we can re-examine them to find the flaw we missed the first time through. We easily found a flaw in ”˜E,' and thereby feel more confident that we've POE'd four wrong answers and fully supported one right answer with logic that flows from ET.


Note: To answer the question, I would spend a total of a nanosecond on these asterisked tangents and focused on the items I MKT'd so I could POE through the AC and then proceed confidently to harder questions.

*I was not thrown by the fact that time, measured backwards from the present, seems, well, backwards.  52 MYA occurred 2MY before 50MYA.  Duh.  I just remembered my 9th grade high school history teacher explaining why the numbers BC or BCE ran from 0-infinity, sort of like the negative numbers on a number line.

**I did not know that nahcolite was a real mineral (I looked it up on Wikipedia later because I wondered about it  -- turns out it is a real colorlous mineral, see http://en.wikipedia.org/wiki/Nahcolite --  but while answering the question I didn't give it 10 milliseconds' thought, b/c it simply doesn't matter)

***I had no idea how long before 52 MYA or after 50 MYA the Eocene epoch endured. And, again, I didn't GAF, as my good friend Nathan might say. All that matters for this question on this test is that it does include 52MYA-50MYA. (I did explore Wikipedia for background info to win trivia night prizes and beer bets with friends at my local pub later, though: http://en.wikipedia.org/wiki/Eocene)

About Scott Cowan: For three decades, Scott has taught, tutored, and counseled clients to help them achieve their highest goals.  He has taught in schools on both coasts of the USA, and in France: every grade, 6-12 and college undergraduates, at least one year each.  Certified to teach English, History, French, and Spanish, he helps students from nearly every school in the Bay Area, and many students from Asia, Europe, and Latin America find acceptance at Great-Fit colleges and Graduate schools, achieve top scores on ACT, AP, GMAT, GRE, HSPT, LSAT, SAT, and SSAT exams. Scott edits academic and professional writing for publication.  His writing, math, and study skills clients see huge improvements in GPA.

Scott has studied at universities in the USA and France.  He has degrees in History, Sociolinguistics, and Education.  Scott aims to help his students become their own best teachers and help all clients set personally meaningful goals, then find creative, rewarding ways to meet them.

Please ask questions and/or suggest corrections to anything that seems confusing... we want to make this the best resource we can for LSAT students. We'll have all the June 2013 explanations up as quickly as possible. Thanks for reading. Tell your friends! --nathan

Crowdsourcing the June 2013 LSAT:  June 2013 LSAT Explanation Central | About this project