Какое максимальное количество ферзей можно разместить на шахматной доске так, чтобы они не атаковали друг друга? На доске размером n*n?

Ответ: 1, при n=1, 2; 2, при n=3; n, при n>=4. Итого на стандартной доске 8*8 - 8:

 1 2 3 4 5 6 7 8
 ___ ___ ___ ___ ___ ___ ___ ___
h | | | | | | | Ф | |
 --- --- --- --- --- --- --- ---
g | | | | | Ф | | | |
 --- --- --- --- --- --- --- ---
f | | | Ф | | | | | |
 --- --- --- --- --- --- --- ---
e | Ф | | | | | | | |
 --- --- --- --- --- --- --- ---
d | | | | | | Ф | | |
 --- --- --- --- --- --- --- ---
c | | | | | | | | Ф |
 --- --- --- --- --- --- --- ---
b | | Ф | | | | | | |
 --- --- --- --- --- --- --- ---
a | | | | Ф | | | | |
 --- --- --- --- --- --- --- ---