Question

Question Statement:

On any given flight, the probability of snakes being present is about 0.05.  

Alex's reaction to the snakes' presence is either sick or tired, and of course she can be sick or tired sometimes even when there are no snakes around. Those are of course inclusive or's because Alex can be sick and tired at the same time.

In particular, when there are snakes on her plane, Alex is sick with probability 0.9, and she is tired with probability 0.8. When there are no snakes on her plane, Alex is sick with probability 0.01 and tired with probability 0.3.

You may assume that the events when Alex is sick and when Alex is tired are conditionally independent, given whether or not there are snakes on her plane.

If Alex is both sick and tired, what then is the probability that there are snakes on her airplane?

Answer 1

Snacks in aeroplane

P(a)=0.9

P(b)=0.8

Ini independentevent condition is

P(a n b)=p(a) p(b)

P(a n b)=0.9 x0.8

=0.72 or 72%