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A and B are two independent events. If P(A) = 0.3 and P(B) = 0.5, then the P(A or B) is equal to:
0.65
0.80
0.15
0.50
0.65
For independent events, directly apply the addition theorem formula P(AтИкB)=P(A)+P(B)тИТP(A)├ЧP(B) without constructing a Venn diagram.
P(A) = 0.3, P(B) = 0.5, and A and B are independent events.
P(AтИкB)=P(A)+P(B)тИТP(A)P(B)
For independent events, directly apply the addition theorem formula P(AтИкB)=P(A)+P(B)тИТP(A)├ЧP(B) without constructing a Venn diagram.
Students often forget to subtract the intersection term P(AтИйB)=P(A)P(B) and mistakenly add only P(A)+P(B).
Identify Given Data
We are given the probabilities of two independent events A and B: P(A)=0.3 and P(B)=0.5.
P(A)=0.3,P(B)=0.5
Use Independence Property
Since events A and B are independent, the probability of both events occurring together is the product of their individual probabilities: P(AтИйB)=P(A)├ЧP(B).
P(AтИйB)=0.3├Ч0.5=0.15
Apply Addition Theorem
The probability of either event A or event B occurring is given by the addition theorem for probability.
P(AтИкB)=P(A)+P(B)тИТP(AтИйB)
Calculate Final Value
Substitute the known values into the equation to compute the final result.
P(AтИкB)=0.3+0.5тИТ0.15=0.65
A is correct because the calculated value of P(A or B) is 0.65.
In competitive exams, independence is frequently combined with conditional probability problems where P(AтИгB)=P(A).