Posted by **sara** on Tuesday, April 10, 2007 at 4:22pm.

If A is a finite set and B is a proper subset of A, prove that |B| < |A|.

Hint: B is finite. What is the union of the disjoint sets B and A - B?

Note: |A| = size of A

## Answer this Question

## Related Questions

- smallest algebra - Let F be a family of subsets of a set X such that empty set ...
- math - Prove that the union of two finite sets is finite. Hint: A U B = (A - B) ...
- calculus - what is the property that distinguishes finite sets from infinite ...
- Set Thoery - (1)Given the sets A={a,b}, B={a,b,c}, C= {b,c,d}. which of these ...
- Finite Math - Sizes of disjoint subsets of a universal set. Assume that A and B ...
- math - Let f:A->B, where A and B are nonempty, and let T1 and T2 be subsets ...
- Set Theory - Given the sets A=[a,b], B=[a,b,c], C=[b,c,d] Prove that if A is a ...
- Discrete Math - For sets A, B, C is a subset of U, prove or disprove (with a ...
- Algebra - Observe the following sets and answer he quesions given below. A = The...
- math - 7. Classify each of the following as true or false. If false, tell why or...

More Related Questions