Kassra prefers to take morining classes but Dr Mataruse usua

Kassra prefers to take morining classes. but Dr. Mataruse usually teaches in the afternoon. If Dr. Mataruse is teaching the class, there\'s only a 10% chance it will be a morning class . If someone else teaches the class, there is a 50% chance it will be a morning class.

a) Kassra decides that he will take the class so long as either Dr. Mataruse is teaching the class or it is a morning class. what is the chance of this happening ?

b) suppose you havent heard when the class is, or who is teaching it, but Kassra has. You find out that Kassara has decided to take the class ( based on his criteria explained in part a) . given this knowledge, what is the probability that Dr Mataruse is teaching the class.

Please answer part B) only and show step by step. Thank you :)

Solution

Kassra prefers to take morining classes. but Dr. Mataruse usually teaches in the afternoon. If Dr. Mataruse is teaching the class, there\'s only a 10% chance it will be a morning class . If someone else teaches the class, there is a 50% chance it will be a morning class.

a) Kassra decides that he will take the class so long as either Dr. Mataruse is teaching the class or it is a morning class. what is the chance of this happening ?

b) suppose you havent heard when the class is, or who is teaching it, but Kassra has. You find out that Kassara has decided to take the class ( based on his criteria explained in part a) . given this knowledge, what is the probability that Dr Mataruse is teaching the class.

Ans.:

Let A is event that Dr. Mataruse is teaching the class and it will be a morning class, B is the event that someone teaches the class and it will be a morning class.

P(A)= 0.1

P(B)= 0.5