Answer:
Total number of way to pick 3 letters is 6C3 = 20.
Step-by-step explanation:
P(E) = 3/6 = 1/2
P(O) = 3/6 = 1/2
The intersection is P(E n O) = P(E)P(O | E)
= 1/2(2/5)
= 1/5
P( E or O but not both) = P(E and not O) + P(O and not E)
(THis step is easier to understand if you shade in a venn diagram for this):
= [ P(E) - P(E n O) ] + [ P(O) - P(O n E) ]
= 1/2 - 1/5 + 1/2 - 1/5
= 1 - 2/5
= 3/5
The P (E or O or both ) is just the union of the two:
P( E U O) = P(E) + P(O) - P(E n O)
= 1/2 + 1/2 - 1/5
= 4/5
