Note that an empty set is included for the set of 11 numbers. That is 1 subset.
Since order doesn't matter for this type of situation, we count the following number of subsets.
1-item subset: 11 choose 1
2-item subset: 11 choose 2
3-item subset: 11 choose 3
4-item subset: 11 choose 4
5-item subset: 11 choose 5
6-item subset: 11 choose 6
7-item subset: 11 choose 7
8-item subset: 11 choose 8
9-item subset: 11 choose 9
10-item subset: 11 choose 10
11-item subset: 11 choose 11
Note that the pattern of these values follows the Fibonacci sequence. If we add all of these values and 1 altogether, then you should get 2048 subsets that belong to the given set {1,2,3,4,5,6,7,8,9,10,11}.
Instead of working out with cases, you use this form, which is 2ⁿ such that n is the number of items in the set. If there is 11 items in the set, then there are 211 possible subsets!
5 subsets of 4 and of 1, 10 subsets of 3 and of 2 adds up to 30.
11
{}, {1}, {2} and {1,2}
As you know 10 dimes is a dollar because 10*10 = 100 and 100 = $1 so if you know that 10 dimes is a dollar you have 1.10 or 1 dollar and 10 cents
-11
5 subsets of 4 and of 1, 10 subsets of 3 and of 2 adds up to 30.
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}
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)
There are 6 such subsets of B.
Number of subsets with no members = 1Number of subsets with one member = 5.Number of subsets with 2 members = (5 x 4)/2 = 10.Number of subsets with 3 members = (5 x 4 x 3 /(3 x 2) = 10.Number of subsets with 4 members = (5 x 4 x 3 x 2)/(4 x 3 x 2) = 5.Number of subsets with 5 members = 1Total subsets = 1 + 5 + 10 + 10 + 5 + 1= 32.A set with n elements has 2n subsets. In this case n = 5 and 25 = 32.The proof in the case that n = 5 uses a basic counting technique which say that if you have five things to do, multiply together the number of ways to do each step to get the total number of ways all 5 steps can be completed.In this case you want to make a subset of {1,2,3,4,5} and the five steps consist of deciding for each of the 5 numbers whether or not to put it in the subset. At each step you have two choices: put it in or leave it out.
x = (1/10)/(10/11) (* means multiply) > x = ((11*1)/(11*10))/((10*10)/(10*11)) > x = (11/110)/(100/110) > x = 11/100 > x = 0.11
To find how many proper subsets there are in a set you can use the formula n^2 -n and if you would also like to find all subsets including improper the formula is n^2 -n +1
11
11/(1/10) = 110 of them.
10 plus 1 is 11.
{}, {1}, {2} and {1,2}
32