Question let d equals ={ 16, 19, 21}, e equals ={ 16, 18, 19, 20} and f equals ={ 15, 17, 18, 19, 21}. list the elements in the set d u e

D U E = { 16, 18, 19, 20, 21 }

Step-by-step explanation:

The symbol U means union of sets.

In union, we take all of the elements of both the sets.

Set D has elements { 16, 19, 21 } and set E has elements { 16, 18, 19, 20 }.

So, we take all their elements for union. The common elements of both the sets are written once.

Therefore, the elements in the set  D U E are { 16, 18, 19, 20, 21 }