Given
d = {x | x is a whole number)
e = {x | x is a perfect square between 49 and 100)
f = {x | x is an even number between 10 and 20)
the expression duf means? (64 and 84 or all whole #s)
the expression d n f means? (12, 14, 16, 18 or 16, 22, 24, 18)
the expression d n e means? (all whole #s or 64, 81)
the expression e n f means? (all whole #s or the empty set)
the expression d (euf) means?
(81, 64, 12, 14, 16, 18 or empty set)