Each matchbox is made from an unlimited pile of matchsticks by collecting 18 matchsticks randomly from the pile. It is known that 0.25 percent of the matches in the pile have a contaminated coat of material. If the matchboxes are made serially one after another what is the expected number of matchboxes that will be made before there is one box with at least one contaminated matchstick?

Each matchbox is made from an unlimited pile of matchsticks by collecting 18 matchsticks randomly from the pile. It is known that 0.25 percent of the matches in the pile have a contaminated coat of material. If the matchboxes are made serially one after another what is the expected number of matchboxes that will be made before there is one box with at least one contaminated matchstick? Select one: O 20 O None of these O 22 O 18