Statement (A): P(S∣B)=1
Using the conditional probability formula:
P(S∣B)=P(B)P(S∩B)
Since B⊆S, we have S∩B=B
P(S∣B)=P(B)P(B)=1
Statement (A) is TRUE.
Statement (B): P(A∩B)=P(A)+P(B)+P(A∪B)
The addition rule for probability states:
P(A∪B)=P(A)+P(B)−P(A∩B)
Rearranging:
P(A∩B)=P(A)+P(B)−P(A∪B)
The given statement has a plus sign instead of a minus sign.
Statement (B) is FALSE.
Statement (C): P(Aˉ∣B)=1−P(A∣B)
Given that event B has occurred, either A occurs or Aˉ occurs:
P(A∣B)+P(Aˉ∣B)=1
Therefore:
P(Aˉ∣B)=1−P(A∣B)
Statement (C) is TRUE.
Statement (D): P(A∣B)=P(B)P(A∩B),P(B)=0
This is the definition of conditional probability.
Statement (D) is TRUE.
Statements (A), (C), and (D) are TRUE.
Statement (B) is FALSE.
The correct answer is: (A), (C) and (D) only.