A cat will not be affectionate toward people unless it is handled when it is a kitten. Since the cat that Paula plans...

Mehran September 15, 2017

@johnny let's break down the argument first.

"A cat will not be affectionate toward people unless it is handled when it is a kitten."

We know "unless" introduces a necessary condition and the negation of the other part of the statement is our sufficient condition.

ATP ==> HK
not HK ==> not ATP

"Since the cat that Paula plans to give to her friend was handled when it was a kitten, that cat will be affectionate toward people."

P: HK

C: ATP

Notice the flaw here. The premise is the necessary condition of our general principle, i.e. HK.

The author then concludes the sufficient condition, i.e. ATP.

We know that you DON'T JUST REVERSE so the flaw here is mistaking necessary for sufficient.

Now let's take a look at answer choice (E):

"Grass seeds will not germinate well unless they are pressed firmly into the ground."

GW ==> PFG
not PFG ==> not GW

"The grass seeds sown in this yard were pressed firmly into the ground, so they will germinate well."

P: PFG

C: GW

Notice this is the exact same flaw, i.e. mistaking necessary for sufficient.

Therefore, (E) is the correct answer.

Hope that helps! Please let us know if you have any other questions.