Solution of problem N321 Laplace probability theory

Solution of problem N321 Laplace probability theory

321. When examining the statutory funds of banks, it is established that one-fifth of banks have a statutory fund in excess of 100 million rubles. Find the probability that among 1800 banks have a statutory fund of more than 100 million rubles:
A) no less than 300;
B) from 300 to 400 inclusive.

Additional information:

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