407. In the communication sequence of signs forming the message, any sign due to interference, independently of the others, is distorted with a probability of 0.002. What is the probability that in the transmitted sequence of 10,000 characters: a) there will be at least 10 distortions; B) the number of distortions will not be more than 20?

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