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Increasing rows columns 3x3 array

1425ApprenticeCombinatoricsCounting Principles

AMC 12B · 2010 · Problem 17

The entries in a $3 \times 3$ array include all the digits from $1$ through $9$, arranged so that the entries in every row and column are in increasing order. How many such arrays are there?

Answer choices

A
18
B
24
C
36
D
42
E
60
0 students attempted0% solvedRating 1425

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