Question 47
Joana must place three tokens on a $5\times5$ board whose squares are numbered 1 through 25, at most one token per square. In how many ways can she do this if:
a) The three tokens have different colors?
b) The three tokens are identical?
c) The tokens have different colors and no two may be in the same row or column?
a) The three tokens have different colors?
b) The three tokens are identical?
c) The tokens have different colors and no two may be in the same row or column?