Answer with Step-by-step explanation:
1.Let p={Aaron , bob ,phill,john,chad}
Number of elements in set p=5
Formula : Number of subset of the set which contain n elements
![2^n](https://tex.z-dn.net/?f=2%5En)
Total number of subset =![2^5=32](https://tex.z-dn.net/?f=2%5E5%3D32)
The subsets which contain neither Aaron nor bob are
{phil},{john},{chad}
,{phil,john},{phil,chad},{john,chad},{phil,john,chad}
There are eight subsets which do not contain neither Aaron nor bob .
Answer given by the method ![2^{5-2}=8](https://tex.z-dn.net/?f=2%5E%7B5-2%7D%3D8)
Where 5= Total number of elements
2= Number of elements in subsets which do not contain
Therefore,answer is correct.
2.A={1,2,3,4,5,6,7}
There are total seven elements
Therefore, total number of subsets =![2^7](https://tex.z-dn.net/?f=2%5E7)
We have to find the number of subsets of A which include 2,4 and 6.
The number of subsets which contain {2,4, 6}
{2,4,6},{2,4,6,1},{2,4,6,3},{2,4,6,5},{2,4,6,7},{1,2,3,4,6},{1,2,4,5,6},{1,2,4,6,7},{2,4,5,6,7},{2,3,4,5,6},{2,3,4,6,7},{1,2,3,4,5,6},{2,3,4,5,6,7},{1,3,4,5,6,7},{1,2,4,5,6,7},{1,2,3,5,6,7},{1,2,3,4,5,7},{1,2,3,4,5,6,7}
Total number of subsets which contain {2,4,6} are eighteen.
Answer given by ![2^{7-3}=2^4=16](https://tex.z-dn.net/?f=2%5E%7B7-3%7D%3D2%5E4%3D16)
The answer is false.
We can not use these method for calculating number of subsets which contain{2,4,6}.