In Each Situation, Indicate Whether the Method of Data Collection

In each situation, indicate whether the method of data collection is biased.
-A professor is considering a new textbook for her introductory statistics class. She wants to choose a book that emphasizes graphing data. A book that she is considering has 530 pages. To estimate the proportion of pages in the book that have displays of data, she randomly generates 20 numbers between 1 and 530. She then records whether or not each selected page contains displays of data.

A) Not biased
B) Biased