Question

In a certain region, there is a 0.1 probability that any checked passerine bird's nest will

contain a cuckoo egg. If three passerine nests are checked, what is the probability that
at least two of them contain a cuckoo egg?

Answer 1

Probability of at least two cuckoo eggs is 0.738.

Explanation:

probability of cuckoo egg = 0.1

probability of not a cuckoo egg = 1 - 0.1 = 0.9

Probability of at least two cuckoo eggs is

= Probability of two cuckoo eggs x probability of 1 not cuckoo egg +

probability of three cuckoo eggs

= 0.1 x 0.1 x 0.9 + 0.9 x 0.9 x 0.9

= 0.009 + 0.729

= 0.738