The full step-by-step solution to problem: 23E from chapter: 2.5 was answered by , our top Math solution expert on 06/21/17, 07:45AM. This textbook survival guide was created for the textbook: Discrete Mathematics and Its Applications, edition: 7th. This full solution covers the following key subjects: infinite, set, contains, countably, show. This expansive textbook survival guide covers 101 chapters, and 4221 solutions. The answer to “Show that if A is an infinite set, then it contains a countably infinite subset.” is broken down into a number of easy to follow steps, and 15 words. Discrete Mathematics and Its Applications was written by and is associated to the ISBN: 9780073383095. Since the solution to 23E from 2.5 chapter was answered, more than 227 students have viewed the full step-by-step answer.