LSAT (Law School Admission Test) flashcards

Determining which arrangements or selections are explicitly or implicitly forbidden by a set of rules.

• Often requires testing proposed scenarios against all rules.
• A single rule violation invalidates an entire scenario.
• Can involve a process of elimination.

Memory trick: Rule Breaks Reveal Invalid Paths.

A direct and unavoidable outcome derived from applying a single, explicit rule to a given condition.

• Results from a direct application of a rule.
• Requires no complex chaining or inference.
• Often the simplest type of deduction.

Memory trick: Rules Apply Directly To Find Facts.

Inferring the specific position or assignment of an element based on a combination of rules and a given condition.

• Often involves identifying remaining available slots.
• Leverages 'greater than' or 'less than' relationships.
• Results in a single, unavoidable assignment.

Memory trick: People Place, Tasks Have Slots.

Determining the position of an element by eliminating all other possible positions based on rules and prior deductions.

• Often occurs when only one valid slot remains.
• Relies heavily on exclusion and fixed positions.
• A powerful technique for 'must be true' questions.

Memory trick: Remove The Impossible, What Remains Is True.

Identifying two elements that, if selected together, lead to a direct violation of one or more given rules, making their simultaneous selection impossible.

• Involves testing hypothetical scenarios.
• Often reveals hidden conflicts between rules.
• A successful contradiction proves impossibility.

Memory trick: Two ideas, one explosion of impossibility.

Determining which arrangements are possible or which items can occupy a specific position, given an additional constraint and all original rules.

• Involves exploring one or more valid scenarios under a new condition.
• Requires careful application of all rules to the new setup.
• Often uses process of elimination for options that violate rules.

Memory trick: Position + Rules = Possible Book!

Applying a set of sequential constraints to determine valid arrangements of elements.

• Each element appears exactly once.
• Rules dictate positions or relative order.
• Systematic checking of options is often effective.

Memory trick: Road Trip Rules: Check every turn!

Determining a statement that is unconditionally true under a specific 'if' premise, by analyzing all possible outcomes.

• Start with the fixed conditions and the 'if' premise.
• Exhaust all possible arrangements under these constraints.
• Identify elements whose positions are constant across all valid arrangements.

Memory trick: If this piece fits, that piece HAS to go there.

A type of grouping problem where numerical constraints (e.g., 'at least one', 'no more than X', 'exactly Y') are used to deduce the exact number of items assigned to each group.

• Sum of items must match total.
• Minimum/maximum constraints are crucial.
• Relative comparisons (e.g., 'more than') help narrow possibilities.

Memory trick: Count carefully, balance the scales, and the numbers will tell the tale.

Identifying a statement that is necessarily true based on a specific premise and the given rules, eliminating all other possibilities.

• Start with the given premise.
• Apply all relevant rules to the premise.
• Look for a consequence that cannot be otherwise.

Memory trick: Chains of Logic: Every link leads to the truth.

A series of logical inferences where the conclusion of one deduction serves as the premise for the next, leading to a definite outcome.

• Start with fixed assignments.
• Apply conditional rules sequentially.
• Use elimination to narrow down possibilities for remaining elements.

Memory trick: One fact pushes the next, until only one path remains.

A set of rules is contradictory if no valid arrangement or scenario can be constructed that satisfies all given conditions simultaneously. Such problems are typically flawed in test design.

• Systematic deduction from all rules reveals conflicts.
• If no valid scenario can be built, the rule set is contradictory.
• In a well-designed test, problems should always have at least one valid solution.

Memory trick: When pieces clash, no puzzle solution can last.

A rule stating one element must precede another element in an ordered sequence. Placing the first element at the end of the sequence violates this rule.

• Establishes a 'before' relationship.
• The 'earlier' element cannot be in the last position.
• The 'later' element cannot be in the first position.

Memory trick: First must always come before next.

Inferring necessary truths or impossible scenarios based on established positions of elements and their rule interactions.

• Start with the most constrained elements.
• Apply rules sequentially to derive new certainties.
• Check all remaining spots for consistency.

Memory trick: Anchor points reveal hidden truths.

A deduction where the placement of one item, combined with specific rules, leaves only one possible position for another item.

• Often triggered by 'next to' or 'immediately' rules.
• Limits the choices for other elements.
• Can initiate a chain of further deductions.

Memory trick: Roses and Zinnias are a pair, Sunflowers avoid ends, Tulips like odd, Violets follow Sunflowers.

Determining which elements can occupy the first position in a sequence by testing each element against all given rules and constraints.

• Test each element individually.
• Ensure all rules are satisfied by the placement.
• Identify elements that violate any rule when placed first.

Memory trick: Who can start the race without tripping on a rule?

A method to determine which elements cannot occupy a specific position by disproving every possible arrangement for that element in the given position.

• Hypothesize each element in the target position.
• Attempt to construct a valid complete arrangement.
• If all attempts fail for an element, it cannot be in that position.
• This method is often used for 'cannot be true' or 'cannot be in' questions.

Memory trick: Each option, test and reject, until none remain to protect.

A technique where a hypothetical assignment is tested against all rules. If it leads to an unavoidable contradiction, that assignment is impossible.

• Involves exhaustive checking of rule interactions.
• Often reveals subtle conflicts not immediately apparent.
• Crucial for 'cannot be true' or 'cannot like' questions.

Memory trick: 7 friends, 3 hobbies, strict rules. K and L stick together. H avoids R. F and G have a conditional friendship.

An 'impossible premise' occurs when a hypothetical condition given in a logic problem directly contradicts one or more of the established rules, rendering the scenario impossible.

• Leads to a contradiction.
• No deductions 'must be true' from it.
• Often tests rule comprehension or identification of impossibility.

Memory trick: If the starting gate is locked, no race can ever truly begin.

When several elements are assigned fixed positions or relationships, deduce the necessary placement of other elements by systematically applying all remaining rules and constraints.

• Fixed positions drastically reduce possibilities.
• Chaining deductions is crucial.
• Identify conflicts with existing rules immediately.

Memory trick: Fixed spots on the map, link them up to find the hidden path.

Identifying all possible positions or values an item can take, given a set of ordering and grouping rules over a fixed sequence (e.g., months).

• Requires systematically testing each potential position for the target item.
• Each tested position must lead to at least one fully valid arrangement.
• Process of elimination for positions that violate any rule is crucial.

Memory trick: Months are fixed, birds fly free (mostly).

Inferring certain truths by isolating a specific condition and systematically exploring its consequences within the given rules.

• Start by assuming the given condition is true.
• Apply all rules that directly relate to the assumed condition.
• Trace the cascading effects of these applications.
• Identify any conclusions that must hold true in all resulting scenarios.

Memory trick: If this, then what must be true?

When an element's position is fixed, other elements whose positions are directly constrained by the first element's position are immediately deducible.

• Fixed positions trigger immediate deductions.
• Look for 'before/after' rules with fixed elements.
• Often the simplest 'must be true' deduction.

Memory trick: One spot shines a light on another's definite place.

Identifying a scenario that cannot occur due to a direct conflict with one or more given rules, often involving numerical or positional gaps.

• Assume the premise (e.g., X is at position Y).
• Apply all rules to that premise.
• Look for a direct contradiction or an unfulfillable requirement.

Memory trick: This piece won't fit, it breaks the whole puzzle.

Systematically check each given option against all established rules to identify the one that satisfies every condition.

• Every rule must be satisfied.
• One violation invalidates an option.
• Process of elimination is effective.

Memory trick: Review the checklist, one item at a time, to confirm it's all good.

Identifying all valid arrangements or placements for a specific element within a given set of constraints.

• Requires systematic testing of all initial valid scenarios.
• Ensures no valid arrangement is missed.
• Helps confirm the full range of possible outcomes.

Memory trick: Hosta's Home Helps Find Ivy's Spot.

A step-by-step process of applying rules and given conditions to determine the positions of elements in a fixed sequence.

• Start with definite placements from rules or conditions.
• Use adjacency and ordering rules to fill in more positions.
• Eliminate options for remaining elements as positions are filled.
• Identify the single remaining possibility for the target position.

Memory trick: Fill the knowns, then watch the unknowns fall into place.

Determining all items eligible for the first position in a sequence, involving multiple interacting ordering, grouping, and exclusion rules.

• Requires careful consideration of all types of constraints.
• Systematic elimination of candidates is essential.
• Often involves checking for direct contradictions or impossibility of fulfilling subsequent rules.

Memory trick: First in line, who's got the green light?

A type of negative constraint where two elements cannot be placed immediately adjacent to each other. This creates 'forbidden zones' around one of the elements.

• Defines spaces where an element cannot be placed.
• Often combined with fixed positions to narrow possibilities.
• Can apply to elements on either side of a given element.

Memory trick: No hand-holding allowed for these two.

Systematically determining all valid placements for a variable by testing each potential position against all interlocking rules.

• Requires breaking down the problem into cases based on the variable's potential positions.
• Each case must be fully tested against all given constraints.
• Interdependent rules often create chain reactions, eliminating multiple possibilities.
• The 'complete and accurate list' must include ALL and ONLY the valid possibilities.

Memory trick: DA's Blocked, E's End, C's No-Go, F Before B: Pinpoint B.

An element is excluded from a position if its placement leads to a direct violation of another rule, even after considering all other possible placements.

• Assumes the element is in the target position.
• Checks if other rules can still be satisfied.
• If no valid arrangement is possible, the element is conditionally excluded.

Memory trick: One bad apple spoils the whole barrel.