Question

Event B is dependent on event A, and event A occurs before event B. Which formula can be used to find the probability of event A?
a. P(A and B)
P(B)

b. P(A and B)
P(B|A)

c. P(A and B)
P(A|B)

d. P(A and B) × P(B|A)
e. P(A and B) × P(B)

Answer 1

Answer:

Option d - $P(A)=\text{P(A and B)} \times P(B|A)$

Step-by-step explanation:

Given : Event B is dependent on event A, and event A occurs before event B.

To find : Which formula can be used to find the probability of event A?

Solution :

Event B is dependent on event A

i.e. The intersection of A and B - A and B

Probability of event B is dependent on event A is P(A and B)

Event A occurs before event B

i.e. B|A

Probability of event A occurs before event B is P(B|A)

Event B is dependent on event A, and event A occurs before event B is

$\text{P(A and B)} \times P(B|A)$

The formula which shows the probability of event A is

$P(A)=\text{P(A and B)} \times P(B|A)$

Therefore, Option d is correct.  

Answer 2

The right answer for the question that is being asked and shown above is that: "d. P(A and B) × P(B|A)." Event B is dependent on event A, and event A occurs before event B. the formula that can be used to find the probability of event A is P(A and B) × P(B|A)