3774. The warehouse receives products from two factories, the products of the first factory being 60%, and the second - 40%. It is known that the average percentage of non-standard products for the first factory is 3%, for the second - 2%. Find the probability that a product taken at random is produced at the first factory, if it turned out to be standard.

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