Solution of problem N3639 probability theory total prob

Solution of problem N3639 probability theory total prob

3639. Three workers produced for changing 60 parts. Worker productivity refers to 1: 2: 3. The first worker produces an average of 95% of suitable parts, the second - 85%, the third - 90%. Find the probability that, at random, taken from among the parts made per shift is of poor quality.

Additional information:

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