Решение задачи N1054 теория вероятностей Лапласа

1054. 400 machines work independently of each other, and the probability of uninterrupted operation of each of them during the shift is 0.7. Find the probability that during the shift they will work without fail: a) 300 machines; b) from 270 to 290 machines.

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