Question

At a particular restaurant, 54% of all customers order an appetizer and 30% of all customers order dessert. If 60% of all customers order an appetizer or dessert (or both), what is the probability a randomly selected customer orders both an appetizer and dessert? Write your answer as a decimal (not as a percentage). (If necessary, consult a list of formulas.) xs ?

Answer 1

We have given,

P(order an appetizer) = 0.54
P(order an dessert ) = 0.30
P(order an appetizer or order an dessert ) = 0.60

P(AUB) = P(A) + P(B) - P(ANB)

Therefore,

P(order an appetizer or order an dessert ) = P(order an appetizer)+P(order an dessert ) -P(order an appetizer and order an dessert )

Substitute here given values,

=> 0.60 = 0.54+ 0.30 -P(order an appetizer and order an dessert )

=>P(order an appetizer and order an dessert ) = 0.24

i.e. The probability of a randomly selected customer order both an appetizer and order an dessert = 0.24