Relationship between Lub of A and Glb of B | Set Theory Homework Solution

[kmikias]

Homework Statement

Two sets A and B.
B contain al the upper bound of A.

whats is the relationship between the lub of A and the glb of B

Homework Equations

The Attempt at a Solution

I am little bit confused , help please

 

[Poopsilon]

I'm assuming we're talking about the real numbers.

Does A=[0,1] and B=(1,∞) satisfy you're requirement?

What about A=[0,1) and B=[1,∞)? In this case in particular, what is the lub of A?

What about A=[0,1] and B=[1,∞)?

And what about A=[0,1] and B=[.5,∞)?