The probability of event A occurring given that event B has already occurred is 0.61. The probability of both events occurring is 0.5. What is the probability of event B occurring?

a) 0.305

b) 0195

c) 0.390

d) 0.820

e) 0.500

D. 0.82

Step-by-step explanation:

P (A|B) = 0.61

P (A∩B) = 0.5

P (B) = ?

The conditional probability formula is:

P (A|B) = P (A∩B) / P (B)

Then, you must transform this formula to get P (B):

P (A|B) * P (B) = P (A∩B)

P (B) = P (A∩B) / P (A|B)

P (B) = 0.5/0.61

P (B) = 0.819

P (B) = 0.82