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Ranking by Elimination
The Orderings Are the Answer Space
Summary
Four out of twenty-four
Four labels can be put in order twenty-four different ways. The item hands you four of them and asks you to select the choice that has the correct ranking. Before you have looked at a single angle, twenty of the twenty-four possibilities are already gone, and the four that remain were not drawn at random.
So read the choices first. They are text, they take three seconds, and they tell you which comparisons the item is actually going to score.
Rank the four angles from SMALL to LARGE.
Even with the angles withheld there is work to do here. Every one of the four choices ends with panel 4. Whatever else is in dispute, all four agree that panel 4 holds the largest angle — which means no amount of staring at panel 4 can change your answer. A position every choice agrees on is a position you never have to judge.
An ordering is a bundle of claims
Choice C reads 3 - 2 - 1 - 4. Unpack it into assertions: panel 3 is smaller than panel 2, panel 2 is smaller than panel 1, panel 1 is smaller than panel 4, and every other pairing that follows from those. Each choice is a package of claims of that kind, and the package is sold whole.
That makes the arithmetic of the item lopsided in your favor. To accept a choice you would have to believe all of its claims. To kill a choice you only have to disprove one of them. Confirmation is expensive, elimination is cheap, so work by killing.
Where the choices disagree
Lay the four side by side, position by position:
| Position | A | B | C | D |
|---|---|---|---|---|
| 1st (smallest) | 3 | 1 | 3 | 2 |
| 2nd | 1 | 2 | 2 | 3 |
| 3rd | 2 | 3 | 1 | 1 |
| 4th (largest) | 4 | 4 | 4 | 4 |
The bottom row is settled and costs nothing. The top row is contested three ways — the choices cannot agree whether panel 3, panel 1 or panel 2 is the smallest — so a verdict about which panel is smallest is worth a great deal here. That one reading, if you can make it, throws out either two choices or three.
This is the point of reading the choices first: it converts a vague instruction ("rank these four") into a short list of specific questions worth answering.
Near-misses, not scrambles
Set the wrong choices against the right one and the family resemblance is obvious. None of them is a reshuffle. Each keeps most of the true order intact and disagrees about a small number of specific pairs — labels traded between positions, everything else left standing.
Two things follow. The first is convenient: because the choices differ from each other only locally, comparing them to each other is fast, and the disagreements jump out. The second is a warning. No wrong choice will look absurd. You will not find the answer by noticing that three of the four are obviously silly, because all four are plausible orderings of four angles that genuinely are close together. Every one of them has to be killed on evidence.
Treat that resemblance as a description of the items you practice on rather than a published rule of the exam — the ADA does not say how its own wrong orderings are built. It is a reliable feature of your practice set, and it shapes how you should read.
Read the choices, then the angles
The expensive order of operations is the natural one: study four angles, rank them from scratch, then go looking for your ranking among the choices. Ranking from scratch means six pairwise comparisons — every panel against every other — and the choices frequently only need one or two of them.
With the choices already read, this stimulus is not asking you to rank four angles. It is asking you which of panels 3, 1 and 2 is the smallest, and then, depending on the answer, at most one follow-up. Panel 4 you can skip entirely.
In degrees: #3 = 77°, #2 = 89°, #1 = 102°, #4 = 117°. Ray length is a distraction — compare the openings near each vertex.
Each of the three wrong orderings here sits a single exchange of positions away from the true one — near-misses, as promised, and every one of them still ending in panel 4.
The takeaway
Twenty-four orderings exist and four are offered, so most of the answer space is eliminated before you start. Read the four choices before the angles: positions where all four agree need no work at all, and positions where they disagree are the only comparisons worth making. Each choice is a bundle of claims that dies the moment any single claim is disproved — and since none of the wrong ones will look absurd, disproving is how you get through them.
Practice Questions
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