Answer:
Explanation:
P= {1,3,5,7,9,11,13,21}
R ={2,4,6,8,10,12}
O={3,6,9,12,15,18}
The union of two sets contain all the elements in either set.
R ∪ O = {2,4,6,8,10,12,3,9,15,18 } [6 & 12 are in both R and O. we have to write only one time]
P U (R ∪ O) = {1,3,5,7,9,11,13,21,2,4,6,8,10,12,15,18}