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2009 AMC 8 Question 21

AMC8 · 2009 AMC 8

Question 21

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 $B.$ What is the value of $\dfrac{A}{B}?$
  1. $\dfrac{64}{225}$
  2. $\dfrac{8}{15}$
  3. $1$
  4. $\dfrac{15}{8}$
  5. $\dfrac{225}{64}$