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June 2017 LSAT
If ecology and the physical sciences were evaluated by the same criteria, ecology would fail to be a successful scien...
on September 17, 2019
Why is E correct? Why is C incorrect?
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on September 20, 2019
Let's break down the argument to see which answer choices follow the same format.
If ecology was evaluated like a physical science (EPS), then it would be unsuccessful (US).
If EPS - - - - -> US
But ecology is a successful science. Therefore it is not being evaluated like a physical science.
not US - - - - -> not EPS
Basically, the passage eliminated the necessary condition (US), which in turn eliminates the sufficient condition (EPS).
You asked why E is correct. I'll diagram it the same way.
If any economic theory were an adequate description (A), then it would be possible to make accurate forecasts (P).
If A - - - - -> P
But it is not possible to make accurate forecasts (This eliminates the necessary condition P). Therefore no economic theory is an adequate description (which eliminates the sufficient condition A).
not P - - - - - -> not A
Make sure to practice your conditional reasoning, including contrapositives like we saw in this example.
Answer choice C does not follow this same pattern.
If future cars are made lighter and stronger (LS), then the number of fatalities will be reduced (FR).
If LS - - - - > FR
It is obvious that future cars will be made lighter and stronger. Therefore fatalities will be reduced.
LS - - - - - > FR
This does not create a contrapositive. It only fulfills the conditional statement from the first sentence.