Solution of problem N1002 Laplace probability theory

Solution of problem N1002 Laplace probability theory

1002. It is known that, on average, 60% of the total number of telephone sets manufactured by the plant is first-class products. What is the likelihood of the fact that the manufactured batch will be:
a) 6 apparatuses of the first class, if the lot contains 10 apparatuses;
b) 120 first class machines, if the batch contains 200 apparatuses?

Additional information:

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