Solution of problem N4114 probability theory total prob

Solution of problem N4114 probability theory total prob

4114. There are 1200 lamps, 450 belong to the first batch, 550 - to the second batch, 200 - to the third batch. In the first batch of 10%, in the second - 8%, in the third - 6% 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)