Question

Please Help! Find the missing probability.

Answer 1

Answer:

The value of P(A∩B) = 143/400 ⇒ answer D

Step-by-step explanation:

* Lets explain how to solve the problem

- P(B|A) is called the "Conditional Probability" of B given A

- Conditional probability is the probability of one event occurring

  with some relationship to one or more other events

- That means event A has already happened, now what is the

  chance of event B

- The formula for conditional probability is  P(B|A) = P(A and B)/P(A)

- You can also write it as P(B|A) = P(A∩B)/P(A) because,

  P(A and B) = P(A∩B)

∵ P(A) = 11/20

∵ P(B|A)= 13/20

∵ P(B|A) = P(A∩B)/P(A)

- Substitute the values of P(A) and P(B|A) in the rule

∴ 13/20 = P(A∩B)/(11/20)

- Multiply both sides by 11/20

∴ (13/20) × (11/20) = P(A∩B)

∴ 143/400 = P(A∩B)

* The value of P(A∩B) = 143/400