Logical Reasoning

PT148 · S1 · Q14 In order for life to exist

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In order for life to exist on the recently discovered planet P23, there must be water on the planet's surface.

Conclusion (so)

There is no life on planet P23.

Evidence

In order for life to exist on planet P23, there must be surface water.

There's no surface water.

Evaluate

This is an argument by contrapositive. There is one premise that gives us a conditional rule, Life → Water Then there is a 2nd premise that says the Outcome of the conditional is not the case. Water. Then the conclusion correctly says that the Trigger must not be the case. Life.

Goal

Let's look for something like

P1: X → Y (conditional) P2: ~Y. (fact) C: ~X. (fact)

14.

The pattern of reasoning in the argument above is most similar to that in which one of the following arguments?

  1. A company must have efficient

    Too Many Conditionals

    There's only supposed to be one conditional. All three claims of this argument are conditional, so it's definitely not replicating the same argument.

    4% picked this

  2. The fact that the suspect

    Weak Premise/Conclusion Match

    This answer does not feel promising, but technically there is a conditional logic premise: Suspect's being flustered → low probability was due to surprise of being guilty The other two ingredients would have to be a premise denying the Outcome: But there was a high probability of being guilty. And then the conclusion needs to deny the Trigger: So, the fact that the suspect was flustered was not due to their being surprised at being questioned.

    2% picked this

  3. Correct

    Oil companies are not buying

    Why this is right

    We have a conditional premise: planning on increasing → would be buying new their drilling drilling equipment We have a premise denying the Outcome: They are not buying new drilling equipment. And our conclusion denies the Trigger: So they are not planning on increasing drilling.

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

    82% picked this

  4. The price of real estate

    Illegal Reversal

    Whereas the original argument was completely valid logic, this is a flawed reversal. It provides a conditional premise: town's economy → price of real estate was improving would increase The other premise should be denying the Outcome, saying "the price of real estate is not increasing". However, the other premise here actually affirms the Outcome and then illegally goes backwards and concludes the Trigger. Original This Answer X → Y X → Y ~Y. Y. ~X. X.

    5% picked this

  5. The exports of a particular

    Bad Relationship Match

    This is also valid logic and also involves a conditional premise being triggered. But this is positive logic, and the original was contrapositive logic. This provides a conditional: Exports decrease → Trade deficit increases The second premise should deny the Outcome and say, "But trade deficit hasn't increased", and then conclude, "Thus exports aren't decreasing". Instead, the other premise affirms the Trigger and concludes the Outcome. Original This Answer X → Y X → Y ~Y. X. ~X. Y.

    7% picked this

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