Solution of problem N1469 Laplace probability theory

Solution of problem N1469 Laplace probability theory

1469. It is established that the consumer service enterprise executes on average 80% of orders on time. For some time, 225 orders were accepted. What is the probability that they will be fulfilled in time:
a) exactly 190 orders;
b) from 174 to 190 orders?

Additional information:

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