Q: If Set X = {1,2,5,7} and Set Y = {1,3,5,6,7,9}, then what is the union of Set X and Set Y?
UNANSWERED.
The correct answer is D.
A: {1,2,3,5,6,7,9} is the right answer.
To find the union of 2 sets, list all the elements from either set. So to get the union, we first include all the elements from Set X: 1,2,5,7.
Then we add in the elements from Set Y = {1,3,5,6,7,9} one at a time: The 1 is already in the union, so we don't need to list it twice. Add in the 3: union = 1,2,3,5,7 The 5 is already in the union, so we don't need to list it twice. Add in the 6: union = 1,2,3,5,6,7 The 7 is already in the union, so we don't need to list it twice. Finally, add in the 9: union = 1,2,3,5,6,7,9 We finished adding all the elements from Set Y to Set X, so we're done. We have the union of Set X and Set Y.
