Question

A big department store employs a total of 180 people. of these 180 people, 27 are managers, 100 are floor assistants, and the rest are helpers. if we choose an employee at random, find the probability that the employee is not a floor assistant.

Answer 1

Among 180 people 27 are managers, 100 are floor assistants and the rest are helpers. Under the rest we mean 180-27-100=53 people.

The event "randomly selected employee is not a floor assistant" is the same as "randomly selected employee is manager or helper". You can count that in total 27+53=80 people form the set of managers and helpers.

Then the probability that randomly selected employee is not a floor assistant is

$Pr=\dfrac{80}{180}=\dfrac{4}{9}.$

Answer: $Pr=\dfrac{4}{9}.$