Andy and Bethany have a rectangular array of numbers with $40$ rows and $75$ columns. Andy adds the numbers in each row. The average of his $40$ sums is $A$. Bethany adds the numbers in each column. The average of her $75$ sums is $B$. Find the value of \(\frac{A}{B}\). The answer should be in the form \(\frac{k}{m}\), where k and m are integers, and please give the value of k + m.

Let's think step by step and output the final answer within \boxed{}.
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