jlgdr wrote:
A sounded too extreme, but still wouldn't it have to be true? Could someone clarify this please?
Disclosure: I picked
Cheers!
J
Dear
jlgdr,
I'm happy to respond.
First of all, remember, the opposite of "
all" is not "
none." The opposite of "
all" is simply "
not all" --- of course, "
all" means 100%, but "
not all" could be 1%, 10%, 50%, 80% or 99.9%.
So, suppose
(A) is false. Suppose it's not true that the "
birds of prey capture and kill every single Spotted Mole that comes above ground." Suppose of an original population of 1000 Spotted Moles on a particular, the birds of prey kill all but 7, and some 7 particularly lucky or particularly fast or crafty Spotted Moles survive. Well, in that case, the birds of prey did not kill "
every single" one, but if there are only 7 left, they are not going to pose much of a threat to the farm. The spotted hawks could kill over 99%, the vast majority of the moles, and even though they didn't kill every last one, it's enough to protect the farms.
Does all this make sense?
Mike
A bit shaky. The conclusion is that there is NO threat. If birds do not kill EVERY spotted mole, there is tiny bit of possibility of threat (even if there are only 7 of them) - it is not "no threat". If conclusion were "there is no significant threat..." it would have made much more sense. D, on the other hand, sounds controversial. Suppose feeding times are not the same, but nothing in the question stem indicates that moles come above the ground ONLY when it's feeding time. They might remain above ground at other times too, and birds can prey on them then. Correct me if I'm wrong..