Hi
dwivedys is correct--this is not a GMAT-like question.
It is an LSAT or LSAT-like question testing technical formal logic skills in a way that GMAT never would.
We have:
Quote:
Only if the electorate is moral and intelligent will a democracy function well.
"Only if" tells us that the electorate's being moral and intelligent are necessary conditions for a well-functioning democracy.
Because they are necessary for a well-functioning democracy, if we don't have either of them, then we won't have a well-functioning democracy. This is what choice C says. Thus, choice C can be properly inferred.
We can't infer choice A because we only know that the electorate's being moral and intelligent are necessary conditions for a well-functioning democracy--we don't know that they are sufficient--we don't know that they will guarantee a well-functioning democracy. For the same reason, we can't infer choice E.
We can't infer choice D because there may be many other reasons why a democracy is not functioning well.
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Here's an analogy:
Only if you have a gas tank and a functioning batter will you be able to drive your car.
We can infer that if you don't have a gas tank or if you don't have a functioning battery then you won't be able to drive your car. This inference is analgous to choice C of this question.
Can we infer that if your car isn't driveable it's because there is no gas tank or because the battery isn't functioning? Of course not, there may be other reasons your car isn't driveable. So, this improper inference is like choice D of this question.
Can we infer that if you do have a gas tank and a functioning battery, you will certainly be able to drive your car? Of course not, because your car may not have tires! So, this improper inference is like Choices A and E of this question.