11) On an $8 \times 8$ chessboard, the rows and columns are numbered from 1 to 8. On each square, Mauro places tokens according to this rule: he looks at the row number and the column number corresponding to the square, adds them, and places as many tokens on the square as the result of the sum. How many tokens does he place in total on the chessboard?
(A) 482,
(B) 576,
(C) $768, \quad$ (D) 1024,
(E) 1152
11. The answer is $\mathbf{( B )}$.

It is convenient to imagine that the placement of tokens occurs in two phases. First, we place on all the cells a number of tokens equal to the number of the row they belong to, then we place on all of them a number of tokens equal to the number of the column.

In both cases, we place 8 times 1 coin, 8 times 2 coins, 8 times 3 coins, up to 8 times 8 coins for the last row or column. Therefore, in each of the two phases, we place $8 \cdot(1+2+\ldots+8)=8 \cdot 36=288$ tokens. The total number of tokens placed is therefore $2 \cdot 288=576$.