Solution of problem N3846 probability theory total prob

Solution of problem N3846 probability theory total prob

3846. The assembly receives parts from two machines: from the first - 70%, from the second - 30%. At the same time, minor defects from the first machine in 10% of cases, and from the second - in 20%. Find the probability that an item taken at random has a minor defect.

Additional information:

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