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Mathematics
Probability
Combined Events
Addition Law
Addition Law
What You Need to Know
Apply the addition law for mutually exclusive events (
P
(
A
)
+
P
(
not
A
)
=
1
P(A) + P(\text{not } A) = 1
P
(
A
)
+
P
(
not
A
)
=
1
).
Apply the general addition law:
P
(
A
∪
B
)
=
P
(
A
)
+
P
(
B
)
−
P
(
A
∩
B
)
P(A \cup B) = P(A) + P(B) - P(A \cap B)
P
(
A
∪
B
)
=
P
(
A
)
+
P
(
B
)
−
P
(
A
∩
B
)
.
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