Cambridge Binomial Probability (1 Viewer)

[thorax94]

During winter it rains on average 18 out of 30 days. Fiver winter days are selected at random. Find, correct to four decimal places, the probability that:

1. The first two days chosen will be fine and the remainder wet,
2. more rainy days than fine days have been chosen.

 

[cineti970128]

1. = (18/30)^2 * (12/30)^3
2. = 5c2 * (18/30)^2 * (12/30)^3