Question

Add the new condition “O lives on the second floor” to the diagram: Now we attack the answer-choices, attempting to construct a diagram for each one. The answerchoice for which a valid diagram cannot be constructed will be the answer. Start with choice (E). Place L on the 4th floor: Now the condition \(\mathbf{K} / \mathbf{P}\) must be placed on either the \(3 \mathrm{~d}\) and 4 th floors, or the 4 th and 5 th floors. This generates two diagrams: In either diagram, \(L\) is on a floor with two apartments, violating the condition \(\mathbf{L}=\) alone. Hence the answer is (E). Note: We presented the answer directly, instead of applying an indirect proof, because we knew the answer is (E)! These types of problems can be very time consuming; so when you come to them on the test, first scan the answer-choices to see whether you can intuitively pick out the answer (or at least spot a likely candidate). If this fails, then come back to the problem later, if you have time, and apply an indirect proof.

Short answer

Choice (E) is the answer because placing L on the 4th floor violates conditions.

Step-by-step solution

Understanding the New Condition

The condition is that "O lives on the second floor." Therefore, we need to adjust our diagram to place O on the second floor, which might affect the other conditions and placements.

Analyzing Answer Choice (E)

We're starting with choice (E), where L is placed on the 4th floor. We immediately know that L must be alone on its floor, as per the condition L = alone.

Placing K and P

Given L on the 4th floor, the condition K/P must be placed. This means one of the pair K or P must be on the 3rd and the other on the 4th or 5th floors.

Checking Validity with L's Condition

In both scenarios of placing K and P, L ends up on a floor that requires more than one apartment, which violates the condition L = alone. Therefore, it's not possible to satisfy all conditions with L on the 4th floor.

Conclusion from the Diagram

Since the condition L = alone is violated in both possible diagrams for choice (E), a valid layout can't be constructed, making (E) the correct answer.

Key concepts

Diagram Construction

Constructing a diagram in logic games is like creating a visual map of the problem. It's crucial for applying new conditions, like our added condition "O lives on the second floor." This condition sets a foundation around which other elements are organized. Start by marking "O" clearly on the second-floor space of your diagram.
Once you've identified this key player, see how it influences the placement of others. This might mean shifting other variables to fit around "O" to keep your original rules intact. Think of it as piecing together a puzzle based on specific rules, where each letter or variable has its unique spot.
To enhance your diagrams:

• Use distinct markers or colors for each variable; it makes tracking them easier.
• Break down multi-step conditions into smaller, manageable visual steps.
• Re-draw as needed, especially when testing multiple scenarios.

Diagram construction provides a strong visual aid in keeping track of complex relationships and constraints.

Answer Choice Analysis

Analyzing answer choices in LSAT logic games requires a strategic review of each option. Start by examining how each choice accommodates all existing conditions without contradiction.
In the context of our exercise, start with the answer choice you believe is most likely correct, as it helps save time. For choice (E), where L is placed on the 4th floor, verify how it fits with the known condition "L = alone."
When evaluating answer choices:

• Check if moving a single element affects the placement of others, given the constraints.
• Look for contradictions, such as the inability to satisfy conditions (like "L = alone") across different choices.
• Try eliminating clear invalid options first, rather than identifying the right one immediately.

Methodical answer choice analysis helps ensure accuracy and reduces the risk of overlooking critical details.

Conditional Reasoning

Conditional reasoning is the backbone of solving logic games effectively. This involves understanding 'if... then...' relationships and applying them to assess variable placements. For instance, in our exercise, if "L is on the 4th floor," then no other variables can be there due to "L = alone."
Mastering conditional reasoning means:

• Identifying the triggering and resulting conditions in the problem.
• Practicing translating verbal clues into logical statements.
• Using conditional chains to predict outcomes of certain placements.

By excelling in conditional reasoning, you can make well-informed choices quickly, recognizing the implications that one choice might have down the line.

Logic Games Strategies

Having a strategic approach to logic games can be a huge time saver. The key is knowing when to draw, when to deduce, and when to guess intelligently.
Consider these strategies:

• **Pre-Diagramming:** Before diving into answer choices, sketch a preliminary layout based on known rules. This helps spot instant contradictions or confirmations.
• **Scenario Testing:** Similar to our exercise, test one choice thoroughly if it stands out, rather than wasting time on all options.
• **Pattern Spotting:** With practice, you'll recognize recurring logic templates that can have predictable outcomes.

Effective strategies not only lead to correct answers but also optimize the time spent on each problem, crucial in a timed test environment.