Three queens and two rooks can be placed on a chess board so that all empty squares are under attack, as has been shown here: 3 queens and 2 rooks covering a 8x8 chess board.

What if we require that all squares are under attack, even those occupied by any of the five pieces?

Source: https://www.amazon.com/-/es/Bernardo-Recam%C3%A1n/dp/048684241X

Three queens and two rooks can be placed on a chess board so that all empty squares are under attack, as has been shown here: 3 queens and 2 rooks covering a 8x8 chess board.

What if we require that all squares are under attack, even those occupied by any of the five pieces?

Source