Solution of problem N3919 probability theory total prob

Solution of problem N3919 probability theory total prob

3919. The warehouse received 1500 products from the first factory and 2000 products from the second. It is known that the average percentage of non-standard products among the products of the first factory is 3%, the second is 2%. Find the probability that a product taken from stock at random will be non-standard.

Additional information:

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