Solution of problem N4060 probability theory total prob

Solution of problem N4060 probability theory total prob

4060. Of the 1000 lamps, 500 belong to the 1st installment, 320 - the 2nd and the rest - 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)