Elementary Set Theory (Discrete)

[rmiller70015]

Homework Statement

Suppose A⊂B⊂C. What is A/B, A/C, and A∪B

Homework Equations

The Attempt at a Solution

This isn't really a homework question, I am just trying to get some exposure to discrete math before I take it in the fall.

The set differences A/B and A/C are both empty sets and the 'or' set is B. I understand the last part, but I'm unsure of why A/B and A/C are empty sets. I understand it has something to do with x∈A but x∉B or C as part of the definition of a set difference. I just need someone to explain it to me.

 

[dpopchev]

You tried with simple examples ?

See here and if more questions arose don't hesitate to ask: https://en.wikipedia.org/wiki/Set_theory#Basic_concepts_and_notation