There are 32 possible subset from the set {1, 2, 3, 4, 5}, ranging from 0 elements (the empty set) to 5 elements (the whole set):
0 elements: {}
1 element: {1}, {2}, {3}, {4}, {5}
2 elements: {1, 2}, {1, 3}, {1, 4}, {1, 5}, {2, 3}, {2, 4}, {2, 5}, {3, 4,}, {3, 5}, {4, 5}
3 elements: {1, 2, 3}, {1, 2, 4}, {1, 2, 5}, {1, 3, 4}, {1, 3, 5}, {1, 4, 5}, {2, 3, 4}, {2, 3, 5}, {2, 4, 5}, {3, 4, 5}
4 elements: {1, 2, 3, 4}, {1, 2, 3, 5}, {1, 2, 4, 5}, {1, 3, 4, 5}, {2, 3, 4, 5}
5 elements: {1, 2, 3, 4, 5}
The number of sets in each row above is each successive column from row 5 of Pascal's triangle. This can be calculated using the nCr formula where n = 5 and r is the number of elements (r = 0, 1, ..., 5). The total number of subset is given by the sum of row 5 of Pascal's triangle which is given by the formula 2^row, which is this case is 2^5 = 32.
If a set has N elements then it has 2N subsets. So you can see that a list of all subsets soon becomes a very big task. For reasonably small values of N, one way to generate all subsets is to list the binary numbers from 0 to 2N. Then, each of these represents a subset of the original set. If the nth digit is 0 then the nth element is not in the set and if the nth digit is 1 then the nth element is in the set. That will generate all the subsets.
thenumber of subsets = 8formula: number of subsets =2n; wheren is thenumber of elements in the set= 2n= 23= 8The subsets of 1,2,3 are:{ }, {1}, {2}, {3}, {1,2}, {2,3}, {1,3}, {1,2,3}
Hi Suppose, I found that number of subsets of set S having n elements can be found by using formula 2^n, where n is number of elements of S. Let S(n) represents number of subsets of set S having n elements. S(n) = 2^n S(n+1) = 2^(n+1)
Well honey, the set {1, 2, 3, 4, 5, 6, 7, 8, 9} has 9 elements, so it will have 2^9 subsets, including the empty set and the set itself. That's a grand total of 512 subsets. Math can be sassy too, you know!
To any set that contains it! It belongs to {2.7}, or {45, sqrt(2), pi, -3/7, 2.7}, or all numbers between 1 and 5.3, or integer multiples of 0.3 or rational numbers, or real numbers, or complex numbers, etc.
The set of real numbers is infinitely large, therefore it has an infinite amount of subsets. For example, {1}, {.2, 4, 800}, and {-32323, 3.14159, 32/3, 6,000,000} are all subsets of the real numbers. There are a few, important, and well studied namedsubsets of the real numbers. These include, but aren't limited to, the set of all prime numbers, square numbers, positive numbers, negative numbers, natural numbers, even numbers, odd numbers, integers, rational numbers, and irrational numbers. For more information on these, and other, specific subsets of the real numbers, follow the link below.
Assuming the question is: Prove that a set A which contains n elements has 2n different subsets.Proof by induction on n:Base case (n = 0): If A contains no elements then the only subset of A is the empty set. So A has 1 = 20 different subsets.Induction step (n > 0): We assume the induction hypothesis for all n smaller than some arbitrary number k (k > 0) and show that if the claim holds for sets containing k - 1 elements, then the claim also holds for a set containing k elements.Given a set A which contains k elements, let A = A' u {.} (where u denotes set union, and {.} is some arbitrary subset of A containing a single element no in A'). Then A' has k - 1 elements and it follows by the induction hypothesis that (1) A' has 2k-1 different subsets (which also are subsets of A). (2) For each of these subsets we can create a new set which is a subset of A, but not of A', by adding . to it, that is we obtain an additional 2k-1 subsets of A. (*)So by assuming the induction hypothesis (for all n < k) we have shown that a set A containing kelements has 2k-1 + 2k-1 = 2k different subsets. QED.(*): We see that the sets are clearly subsets of A, but have we covered all subsets of A? Yes. Assume we haven't and there is some subset S of A not covered by this method: if S contains ., then S \ {.} is a subset of A' and has been included in step (2); otherwise if . is not in S, then S is a subset of A' and has been included in step (1). So assuming there is a subset of A which is not described by this process leads to a contradiction.
There is no such number. The empty set is a subset of rational numbers and, by definition, it contains no numbers so nothing that can be common to any other subset.Alternatively, all rational numbers less than -1 and all rational numbers greater than 1 are subsets of rational numbers. There is no number common to them.
32
If a set has N elements then it has 2N subsets. So you can see that a list of all subsets soon becomes a very big task. For reasonably small values of N, one way to generate all subsets is to list the binary numbers from 0 to 2N. Then, each of these represents a subset of the original set. If the nth digit is 0 then the nth element is not in the set and if the nth digit is 1 then the nth element is in the set. That will generate all the subsets.
thenumber of subsets = 8formula: number of subsets =2n; wheren is thenumber of elements in the set= 2n= 23= 8The subsets of 1,2,3 are:{ }, {1}, {2}, {3}, {1,2}, {2,3}, {1,3}, {1,2,3}
5 subsets of 4 and of 1, 10 subsets of 3 and of 2 adds up to 30.
Hi Suppose, I found that number of subsets of set S having n elements can be found by using formula 2^n, where n is number of elements of S. Let S(n) represents number of subsets of set S having n elements. S(n) = 2^n S(n+1) = 2^(n+1)
It belongs to any set that contains it: The set of numbers between 3 and 4, The set containing only the number 3.1414 repeating, The set containing 1, 3.1414 (r) , and sqrt(37) The set of rational numbers, The set of real numbers, etc
There are infinitely many subsets of real numbers. For example, {2}, {2, 3}, {2.3, pi, sqrt(37)}. It is, therefore, not possible to list them.The main subsets of real numbers are the rational numbers and irrational numbers.Irrational numbers can be split into transcendental numbers and polynomial roots.Rational numbers contain the set of integers.Integers contain the set of natural numbers.Natural numbers contain the set of counting numbers.
To get the number of subsets of size less than 2:Total number of subsets of a set of size N is 2NTotal number of subsets of size 1 is 100Total number of subsets of size 0 is 1Total number of subsets of size 2 is 100*99/2 = 4950Sum up: 100 + 1 + 4950 = 5051Subtract this from total subsets: 2100 - 5051 (Answer)
natural numbers integers and whole numbers