Step-by-step explanation:
p union ( Q union R)
let solve for d elements inside d bracket
p = 1,6,10,14 Q = 1,5,11
R = 3,5,10,11
union means joining elements that is p with R.if there is occurrence just pick one.
(Q u R ) = ( 1,3,5,10,11)
so p u ( Q u R ) = ( 1,3,5,6,10,11,14)
