UPSC NDA I and II 2020 Math Solved Paper

Number of proper subset of any set of n elements =2n−1
Here given set ={1,2,3,4}
Number of proper subset =24−1=16−1=15
Proper subset ={(1),(2),(3),(4), (1,2),(1,3),(1,4)(2,3), (2,4),(3,4), (1,2,3)(1,2,4), (1,3,4),(2,3,4)(ϕ)}
Now, A is superset of B, if B is proper set of A, but B is not proper set of A.
i.e. B≤A but A⊄B. Then A≥B.
So, superset of {3} are {(3),(1,3),(2,3),(3,4), (1,2,3),(1,3,4)(2,3,4)}
Hence, number of superset of {3}=7.