Bunuel wrote:
3. How many different subsets of the set {0, 1, 2, 3, 4, 5} do not contain 0?
A. 16
B. 27
C. 31
D. 32
E. 64
Consider the set without 0: {1, 2, 3, 4, 5}. Each out of 5 elements of the set {1, 2, 3, 4, 5} has TWO options: either to be included in the subset or not, so total number of subsets of this set is 2^5=32. Now, each such set will be a subset of {0, 1, 2, 3, 4, 5} and won't include 0.
Answer: D.
Hi Bunuel,
I did this exercise as follows:
I eliminate the 0, so i have the following set: (1,2,3,4,5). Now, i use combinatorics.
Set containing 5 elements: 5C5=1
Set containing 4 elements: 4C5=5
Set containing 3 elements: 3C5=10
Set containing 2 elements: 2C5=10
Set containing 1 elements: 1C5=5
So, the total of posibilites are 31. What am I missing here¿??
Thanks in advance
You are missing 1 empty set, which is a subset of the original set and also does not contain 0.
Hope it's clear.