2•2

The problem asks for the two digits that precede the number 9 in the permutation of four numbers chosen from 1 to 30, where even numbers are red and odd numbers are green. The final digit of the permutation is 9, which is stated to be the last digit of the product.

We can infer that the product of the numbers before 9 ends with 1 because \(9 \times 1 = 9\), and this information is crucial for solving this problem. The key is to determine which combination of the first three numbers results in a product ending with 1.

Try combinations or logical reasoning involving mod 10 of the numbers. One potential pair that works given these constraints is 2, 2, and 5, since:

• \(2 \times 2 \times 5 = 20\), which ends with 0
• Multiplying 0 by 9 gives a digit ending in 9

Thus, the digits that satisfy this condition and result in 9 when included are 2, 2, 5.