math
posted by sara .
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
Respond to this Question
Similar Questions

calculus
what is the property that distinguishes finite sets from infinite sets (give examples of each to accompany explaination). finite sets are countable. Infinite sets are not. so what would be an example of an infinite set? 
math
Prove that the union of two finite sets is finite. Hint: A U B = (A  B) U (B  A) U (A ∩ B) where U = union and ∩ = intersection 
smallest algebra
Let F be a family of subsets of a set X such that empty set is the element of F. A subset A of X belongs to F1 if and only if either A is a subset of F or complement of A is the subset of F. A subset B of X belongs to F2 if and only … 
Set Theory
Given the sets A=[a,b], B=[a,b,c], C=[b,c,d] Prove that if A is a subset of B and B is a subset of C then A is a subset of C 
Set Thoery
(1)Given the sets A={a,b}, B={a,b,c}, C= {b,c,d}. which of these sets are: (i) Equal (ii) Comparable (iii) Subset (2) Prove that if A is a subset of B and B is a subset of C then A is a subset of C 
Algebra
Observe the following sets and answer he quesions given below. A = The set of all residens in Mumbai. B = he set of all residens in Bhopal. C = he sets of all residents in Maharashtra. D = The sets of all residents in India. E = The … 
math
Let f:A>B, where A and B are nonempty, and let T1 and T2 be subsets of B. a.Prove that f^1(T1 U T2)= f^1(T1) U f^1(T2). b.Prove that f^1(T1 intersects T2) = f^1(T1) intersects f^1(T2). I think once I see a I can do b. c. … 
Finite Math
Sizes of disjoint subsets of a universal set. Assume that A and B are disjoint subsets of U, and that n(U)=95, n(A)=30,and n(B')=61. Find n(A¿B'). 
Discrete Math
For sets A, B, C is a subset of U, prove or disprove (with a counterexample) the following: If A is a subset of B, B is not a subset of C, then A is not a subset of C, 
math
Define A relation S for subset of R by S=[{A,B:ACR,B is improper Subset to R,[A/B]u[B/A]is finite prove that s is an equivalent relation and the family of finite subset of R one equivalent class