I am having trouble with the following question:
During winter it rains on average 18 out of 30 days. Five winter days are selected at random. Find (4 d.p) the probability that:
(a) the first two days chosen will be fine and the remainder wet
My approach is this is an ordered selection:
I have defined p = it will rain = or 0.6
q = 1 - 0.6 = 0.4
The answers I have are yielding 0.0124.
(b) more rainy days than fine days have been chosen
P(3 rainy days) =
P(4 rainy days) =
P(5 rainy days) =
= 0.3456 + 0.2592 + 0.007776
The answers are yielding 0.7102
I wonder where I am going wrong
TIA for any assistance!