As a part of a customer loyalty program, a restaurant's computer chooses orders at random to receive a free appetizer. Each order has a 1 in 18 chance of receiving a free appetizer. (Each order is limited to one
free appetizer.) Let X be the number of orders the restaurant fills in a day until they give away the first
appetizer. Assume that each order getting the appetizer is independent.
Find the probability that the restaurant first gives away an appetizer on the 6th order of the day.