probability statistics

Question

the sample space s= ( E1,E2,E3,E4,E5,E6,E7,E8,E9,E10,E11) and A=(E5,E6,E7,E8) and B=(E5,E7,E9,E11)

what is A interaction B?

what is the A union of A and B?

Answer 1

A intersection B is the elements A and B have in common: E5 and E7

A union B is the elements that are either in A or B: E5, E6, E7, E8, E9, E11