Solution of problem N4073 probability theory total prob

Solution of problem N4073 probability theory total prob

4073. Of 1000 lamps, 270 belong to the 1st installment, 640 to the 2nd and the rest to the 3rd installment. In the first batch of 6%, in the second 5%, in the third 4% of defective lamps. One lamp is selected at random. Determine the probability that the selected lamp is defective.

Additional information:

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