Self-study
Putting a tap in a healthy maple that has a trunk 12 or more inches in diameter will not harm the tree. ██████ ███████ ███ ███████ ███ ████████ ██████ ███ ███ ██ ██████ ███ ██████ █████ ██████ ███ █████ ██████ ████████ ██ ████ ███ █████ ███████ ███████ ██ ███ ███ ██████ ███ ███ ███ ███ ███████ █████████████ ██ ██████
Objective: Must Be True Questions
Must Be True questions present a series of claims in the stimulus, then ask us to provide an additional claim that can be validly inferred (i.e. on the spectrum of support, our answer choice must be super-duperly supported).
So it’s highly beneficial to spend time up front wrapping your head around the stimulus – simplifying or diagramming grammatically-complex claims, splitting out combined claims into two or more separate claims, etc. – and the dream is to generate your own inference(s) to proactively seek out in the answer choices.
That’s not always practical (sometimes it’s just hard, and sometimes there are too many to track), in which case using process of elimination – measuring each answer choice against the stimulus to ask “does this follow?” – is completely fine. But process of elimination or no, you need a crystal clear understanding of the stimulus.
As you evaluate the answer choices, remember that in general, weak claims are more likely to be true than strong claims – even without context, it is more likely that some glubsters are flubsters than it is that all glubsters are flubsters.
Distilling The Premises
In this question, knowing when you can and cannot split up complex claims is quite important. Behold:
Sentence 1
If a maple is healthy and it’s big, tapping it won’t harm the maple.
(It turns out Sentence 1 is quite important, so here’s the contrapositive for your convenience:)
If you harmed a maple by tapping it, it was either unhealthy or not big.
Sentence 2
Silver maples can be tapped.
Red maples can be tapped.
Manitoba maples can be tapped.
Sentence 3
Sugar maple best maple.
Sugar maple most sugar.
Notice how we didn’t split the first sentence up, but did split up the second. That’s because these claims have different logical structures. In Sentence 1, both terms in the sufficient condition (i.e. healthy & big) must be fulfilled to trigger the necessary condition (no harm). In Sentence 2, you don’t need to be a silver maple and and red maple and a Manitoba maple to be tapped – any of them can be tapped.
(It turns out Sentence 2 doesn’t matter at all in this question, but still.)
Anticipating the correct answer’s particular inference (or forming the broad idea that it’ll be related to Sentence 1) is somewhat reasonable here, but as long as you’ve boiled these claims down so you have them clear in your head (or on paper), you’ll be all right.
18.
If the statements above are █████ █████ ███ ██ ███ █████████ ████ ████ ██ █████
a
A maple whose █████ ██ ████ ████ ██ ██████ ██ ████████ ██ █████████ ██ ██ ██ ██████ ██ ████████
PART 1: WTF DOES (A) EVEN SAY?!?
On a cold read of (A), you might have parsed it this way, either in your head or in your formal diagram:
Hard-Mode English: If you Tapped a maple and you Harmed it, then if it’s Big, it’s Unhealthy.
Hard-Mode Logic: Tapped & Harmed → (Big → Unhealthy)
That’s rough to work with. But there are a few (albeit advanced) techniques to translate embedded conditionals like this one into forms that are much easier to comprehend. The linked lesson gives a thorough guide to all the moves you’re allowed to make. Here we’re just gonna use some of them and explain why they work.
First, you can get rid of the whole Tapped term by folding it into Harmed, because we’re never dealing with a situation in which the maple isn’t tapped. We’re always tapping the maple. So “Harmed” just means “Harmed-by-tapping” now, okay?
Better-Mode English: If you Harmed a maple, then if it’s Big, it’s Unhealthy.
Better-Mode Logic: Harmed → (Big → Unhealthy)
Now you’re allowed to move “Big” from the right side to the left and connect it with an “and,” like so:
Best-Mode English: If you Harmed a maple and it’s Big, then it’s Unhealthy.
Best-Mode Logic: Harmed & Big → Unhealthy
Why? Test it out by looking at the Better-Mode version again. Learning that something is Harmed triggers the big rule, and then learning it’s Big triggers the smaller rule, making the thing Unhealthy.
PART 2: WHY (A) MUST BE TRUE
So let’s work with that reading of (A): If you harm a big maple, it must be unhealthy.
As it happens, I own a maple tree. It’s a big maple tree, and I would love to tap it to make some syrup, but I really don’t want to harm it because it was my grandmother’s tree.
Well Sentence 1 says that if you check two boxes you 100% for sure will not harm the tree. The two boxes are big (oh nice my tree is big) and healthy (I have gotten bored and started skimming).
So… my tree is good, right? Let’s go make some syrup!
But oh no! Turns out we harmed the tree. I thought we were 100% good if we checked the boxes, though! Why didn’t the no harm guarantee apply to my situation?
Well, it wasn’t the big box – my tree is big. So it must have been the healthy box.
My tree must be unhealthy, because otherwise the “no harm guarantee” would apply.
b
The healthiest maple █████ ███ ███████ █████ ████ ███ ███████ ███████
There are some absolute vs. relative shenanigans afoot here. The stimulus does feature some relative claims (e.g. Sugar maple best maple), but the claims about health and size are absolute: a tree is either healthy or it’s not, it’s either 12in+ or it’s not. This pattern – attempting to draw relative inferences from absolute claims – is common in MBT and MSS wrong answer choices.
c
A maple tree ████ ███ ████ ██████ ████ ███████ ████ ██████ ████
(C) might be a true claim in the real world, but that doesn’t make it a valid inference from our premises.
The concept of a lot of sap / a little sap never appears in the stimulus. The closest we get the claim about sugar maples – they have a lot of sugar in their sap.
You can’t draw a valid inference about a concept that never appears in the stimulus.
d
Putting a tap ████ ██ █████████ █████ ████ ████ ██ ████ ████ ██ ██████ ██ ████████ ████ ████ ███
This applies the inverse of Sentence 1, which is a nono.
Sentence 1: If a maple is healthy and it’s big, tapping it won’t harm the maple.
(D): If a maple is unhealthy and it’s small, tapping it will harm the maple.
e
The maple trees ████ ████████ ████ ███ ██████ █████ ███ █████ ███████
(E) might be a reasonable thing to think given the facts we’re presented. If the sugar maple really is the best maple, it would make sense that it’s the most used kind of maple.
But we’re lawyers, baby! We’re not getting paid to be reasonable, we’re getting paid to be nitpicky! In a MBT question, the introduction of any assumption – no matter how reasonable – kills the answer choice. The assumption that good trees are commonly used, reasonable though it may be, makes (E)’s inference fall short of validity.