Whilst I enjoy rebuttal and discussion, I am keenly aware I have yet to win a single point in presenting a re-rebuttal. However, hope springs eternal, so here goes:
NO FLYING DOGS RE-REVISITED
PROBLEM:
39. If no dog can fly, but some dogs can sing, then:
A. Some dogs can fly, and sing. B. All dogs can't fly, or sing. C. Some dogs can't sing, or fly. D. Some dogs can't fly, but can sing.
I would submit that as; NO dogs fly/SOME sing. Excludes answers A.C.D. As they, state SOME can fly, and we know NONE can fly.
Answer B. is also excluded because it states, "All dogs can't fly, or sing" (ALL can't sing) when we know SOME can.
Ipso fatso: ALL is not SOME, and SOME is not ALL.
Merriam-Webster Online Dictionary
1 a : the whole amount or quantity of <needed all the courage they had> <sat up all night> b : as much as possible <spoke in all seriousness>
2 : every member or individual component of <all men will go> <all five children were present>
3 : the whole number or sum of <all the angles of a triangle are equal to two right angles>
4 : EVERY <all manner of hardship>
5 : any whatever <beyond all doubt>
1 : being an unknown, undetermined, or unspecified unit or thing <some person knocked>
2 a : being one, a part, or an unspecified number of something (as a class or group) named or implied <some gems are hard> b : being of an unspecified amount or number <give me some water> <have some apples>
3 : REMARKABLE, STRIKING <that was some party>
4 : being at least one -- used to indicate that a logical proposition is asserted only of a subclass or certain members of the class denoted by the term which it modifies
"Therefore, "some dogs can't fly, but can sing" is true."
For that to be true, at least one dog must be able to fly, which is false, as NO dogs can fly.
However, if we were to change the animal to say, Pigs. Then you would be correct, as we all know pigs can fly. On the other hand, I don't know if they can sing.
10/4 comeback.