Defective gaskets
Question
Suppose you're working in a parts manufacturing plant, and you're running quality analysis on the gasket production line. Gaskets produced by your company will be defective 1% of the time, and are distributed to customers in packs of 20. Your company has a policy where if 2 or more of the 20 gaskets in a given pack is defective, they will replace the entire package for free. What proportion of packages does the company need to replace?