Logical ReasoningDifficulty: Medium

PT124 S2 Q7 Explanation

In Western economies, more energy

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsNecessary Assumption

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Stimulus

In Western economies, more energy is used to operate buildings than to operate transportation. Much of the decline in energy consumption since the oil crisis of 1973 is due to more efficient use of energy in homes and offices. New building technologies, which make lighting, heating, and ventilation systems more efficient, have from now they will save more than $200 billion per year (calculated in current dollars).

What this question is testing

Necessary Assumption

Your task

Find the assumption the argument requires in order for its conclusion to hold.

Common trap

Answers that would help the argument but aren't strictly required (sufficient, not necessary).

Winning move

Negate each choice — the right one breaks the argument when negated.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
7.

On which one of the following assumptions does the

Answer choices

  1. Correct79% picked this

    Technology used to make buildings energy efficient will not become prohibitively expensive over

    Why this is right

    Answer A is correct.

    Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.

  2. Trap1% picked this

    Another oil crisis will occur in the next 50 to

  3. Trap1% picked this

    Buildings will gradually become a less important consumer of energy

  4. Trap8% picked this

    Energy bills in the West will be $200 billion lower in the next 50

  5. Trap11% picked this

    Energy-efficient technologies based on new scientific principles will be introduced in the next 50

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