PrepTest 120 · Section 1 · Question 21 (Parallel Flaw)

Step 1 · Pre-Question Guidance · read this first

Question type

Parallel Flaw

The one idea it tests

Inferring that a part holds a top or bottom rank just because the whole group it belongs to holds that rank.

The basic logic

X-Ray the argument: a whole (a system, a group) is ranked best or worst among its kind, so a particular piece of it is ranked best or worst among pieces of that kind. That is a Team-to-Star Mix-Up. Find the choice that moves from a superlative about a whole to the same superlative about a component.

Tiny words that decide it

“most”
“least”
“therefore”
“its”

Playground logic

Marcus says our soccer team is the worst in the league, so our goalie must be the worst goalie in the league. That jumps from the team to one star: a Team-to-Star Mix-Up. A team can lose every game while its goalie is a wall.

Step 2 · The kid story

Marcus Blames the Goalie

The Lincoln Lizards lost every soccer game this season. "We're the worst team in the whole league," Marcus groans at lunch. "So Owen must be the worst goalie in the whole league." Owen drops his sandwich. "Hey!" Priya calmly opens her juice box. "Marcus, Owen blocked forty shots. Our forwards never scored. A team can be the worst while one player on it is great." Marcus folds his arms. "But he's ON the worst team." "Being on a team isn't the same as being the whole team," Priya says. Kevin adds, "Like how a T. rex was the scariest dinosaur, but its tiny arms weren't the scariest arms." Everyone stares. "That actually works," Lulu admits, writing it on her clipboard.

Step 3 · Try the model question

The Lincoln Lizards are the worst team in the league. Therefore, Owen, their goalie, is the worst goalie in the league.

Which argument below shows flawed reasoning most like Marcus's?

Step 4 · The courtroom tale

The Case of the Losing Orchestra

At the music contest appeal, attorney Felix Monroe pointed at the defendant. "Your Honor, the Riverside Orchestra placed dead last in the state. Therefore, their flute player is the worst flute player in the state, and she should lose her scholarship." Mr. Whitfield stood, adjusting his suspenders. "Counselor, did the judges score the flute alone?" "Well, no. They scored the orchestra." "Then you have scored a whole and handed the grade to one part. The drums may have been dreadful while my client played like a songbird." The judge sighed. "Mr. Monroe, a last-place group does not prove a last-place member. Scholarship stays."

Step 5 · Work the real question

Open PrepTest 120, Section 1, Question 21 in your official copy from LSAC (for example in LawHub) and read it there.

Your answer

How to apply it

X-Ray the original: find the whole, the ranking it gets, and the part that inherits the same ranking. Write the skeleton in letters: whole W is the most (or least) of its kind, so part P of W is the most (or least) of its kind. Then check each choice's skeleton. Reject choices with a different flaw, ones that compare averages to individuals, ones that move between two different products, or ones without any whole-to-part step.