What four factors were used to make this product game board 9. 15 18. 21? 30 35. 36 42 49

First, let us factor each number into their prime factors:

9 = 3 x 3

15 = 3 x 5

18 = 2 x 3 x 3

21 = 3 x 7

30 = 2 x 3 x 5

35 = 5 x 7

36 = 2 x 2 x 3 x 3

42 = 2 x 3 x 7

49 = 7 x 7

The four factors that were used to come up with the product game are

2, 3, 5, and 7