Solution of problem N5118 probability theory

Solution of problem N5118 probability theory

5118. In a batch of 60 identically packaged articles, articles of two grades are mixed, with 40 of these articles being of the first class, and the rest of the articles of the second class. Find the probability that two products taken at random will be: a) of the same sort; b) different varieties.

Additional information:

Detailed solution. Decorated in Microsoft Word 2003 (Quest decided to use the formula editor)