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2019 AMC 10A Question 20

AMC10 · 2019 AMC 10A

Question 20

The numbers $1,$ $2,$ $\dots,$ $9$ are randomly placed into the $9$ squares of a $3 \times 3$ grid. Each square gets one number, and each of the numbers is used once. What is the probability that the sum of the numbers in each row and each column is odd?
  1. $\dfrac{1}{21}$
  2. $\dfrac{1}{14}$
  3. $\dfrac{5}{63}$
  4. $\dfrac{2}{21}$
  5. $\dfrac{1}{7}$