MathDB

Albrecht fills in each cell of an

8 \times 8

table with a

0

or a

1

. Then at the end of each row and column he writes down the sum of the

8

digits in that row or column, and then he erases the original digits in the table. Afterwards, he claims to Berthold that given only the sums, it is possible to restore the

64

digits in the table uniquely. Show that the

8 \times 8

table contained either a row full of

0

’s or a column full of

1

’s

Problem Statement