Question

It has been estimated that about 30% of frozen chicken contain enough salmonella bacteria to cause illness if improperly cooked. How many would a consumer expect to buy until she gets her first contaminated chicken?

a) 3
b) 3.33
c) 3.6
d) 2.52

Answer 1

b) 3.33

Explanation:

In this case they tell us that 30% of chickens are contaminated, which means, to know how many I must buy to have my first contaminated chicken, I must divide the contaminated quantity that I need to know, that is 1 by the probability, that is 30 % or 0.3

1 / 0.3 = 3.33

Which means I have to buy 3.33 chickens to probably find my first damaged chicken.