Solution of problem N1387 Laplace probability theory

Solution of problem N1387 Laplace probability theory

1387. Workers of the store found that on average 75% of vacuum cleaners do not require additional adjustment when selling. In a batch of 110 vacuum cleaners, find:
a) the most probable number of vacuum cleaners that do not require additional adjustment, and calculate the probability corresponding to this event;
b) the probability that additional adjustment will not require 80 to 95 vacuum cleaners.

Additional information:

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