Mr. D can make 3 different arrays using the factors of the number 9, which are 1x9, 9x1, and 3x3, making the total number of arrays odd.
The question seems to be about arrays and factors related to the number 9. In mathematics, an array is a way of organizing objects into rows and columns. Since the number 9 has positive factors 1, 3, and 9, we can create two arrays for each pair of different factors.
For the factor pair (1, 9), we can arrange the pictures in 1 row of 9 or 9 rows of 1. For the factor pair (3, 3), we can have 3 rows of 3 or 3 columns of 3, but in this case, it represents the same array.
Therefore, for the number 9, we have a total of 3 different arrays: 1x9, 9x1, and 3x3.
Checking if the number of arrays is odd or even, we see that we're left with three arrays, which means the number of arrays is odd.