9514 1404 393
Answer:
no; 1+1=2, a number not in the set
Explanation:
A set is closed under addition if the addition of any two members of the set results in a member of the set.
0 + 0 = 0 . . . in the set
0 + 1 = 1 . . . in the set
1 + 0 = 1 . . . in the set
1 + 1 = 2 . . . not in the set. The set is not closed under addition.