Posted by Bryan on Thursday, January 26, 2012 at 7:57pm.
Assume that the set S has 7 elements.
How many subsets of S have at most 3 elements

Finite MAth  Reiny, Thursday, January 26, 2012 at 8:26pm
The total number of subsets = 2^7 = 128
This includes the null set
So what we want is
the null set, the set of singles, the set of doubles and the set of triples
= 1 + C(7,1) + C(7,2) + c(7,3)
= 1 + 7 + 21 + 35
= 64
So the number of subsets with at most 3 elements is 64
Answer This Question
Related Questions
 math  Assume that the set S has 14 elements. How many subsets of S have at most...
 Math  Assume that the set S has 10 elements. How many subsets of S have at most...
 Combinations  Assume that the set S has 10 elements. How many subsets of S have...
 Set Theory  Let the Universal Set, S, have 136 elements. A and B are subsets of...
 math  Let Pn be the set of all subsets of the set [n]={1,2,…,n}. If two ...
 Math(combinations) Help  Let Pn be the set of all subsets of the set [n]={1,2...
 math  For the set X={m,n.p,q,r,s}, let R be the relation on P(X) (power set) ...
 Algebra  Suppose Set B contains 69 elements and the total number elements in ...
 math  for a set of three elements find the number of different subsets of 2 ...
 Math  I'm new to this but.. how many subsets does a five element have. How many...
More Related Questions