Probabilities

Question

A restaurant messes up one order in three. What is the probability that, if you eat there three times this month, they ever mess up your order? (Assume independence)

Answer 1

Hi Kenny,

 

There are a couple of ways to solve this.  I will find the probability of getting 3 good and subtract it from the total probability.

 

if they mess up one in three the probability of getting an order that is messed up is 1/3

 

that means that the probability of getting one that is good is 2/3

 

one way to find the answer is to find the probability of getting 3 consecutive good orders and then subtract that from 1.

This would tells us the probablility of getting at least one that is messed up

 

(2/3) *(2/3) * (2/3)  = 8/27  (probablitly of 3 consecutive good orders

 

1 - 8/27 = 19/27  (probability of at least one being messed up

 

 

Hope this helps