Solve the below:
We have to prove that the problem is NP -complete by reduction from Vertex-cover.
Q: Given a collection of sets { S1, S2 ,...., Sn} and a positive integer K. Does there exist a set T with at most K elements such that
T ∩ Si≠Ø , 1≤ i ≤n?
[we can use the edges on a graph to create the sets in the collection ]