Identify what you can properly conclude from the given premises:P: not H → not MP: M–some–BC: ?

Halima123 August 28, 2016

Negation of "some"

Wouldn't "M-some-B" translate into/contrapositive into "B-most/all-M?" Why is the correct contrapositive "B-some-M?"

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Mehran August 30, 2016

@Halima123 "some" means "at least one."

So "M-some-B" means at least one M is a B.

The only thing we can properly conclude from this is that at least one B is also an M.

All or most is not necessarily true.

Hope this helps! Make sure you watch our video lesson on Quantifiers for a more in-depth discussion of these concepts.

Hans April 5, 2017

During the lesson somewhere I also ran into the notion that the contrapositive of some is most.

What is the contrapositive of most?

Mehran April 21, 2017

@Hans quantifiers do not have contrapositives.

The issue is whether "some" and "most" are reversible. They are reversible and here are the rules:

When you reverse "most" it become "some." So for example, A-most-B would become B-some-A.

When you reverse "some" it stays "some." So for example B-some-C would become C-some-B.

Hope this helps! Make sure you rewatch our video lesson on Quantifiers if you are still unsure about these concepts. We use some examples that should clarify it for you.