3663. 30% come from the first machine to the assembly, 25% from the second, 20% from the third, and 25% from the fourth. Among the parts of the first machine, 0.2% is defective, the second is 0.1%, the third is 0.25%, and the fourth is 0.3%. Find the probability that the part received for assembly will be defective.

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