Explanation:
If y is largest number, you want y, and the two next smaller even integers smaller than y - i.e. y, y-2, and y-4
The sum of these is y + (y-2) + (y-4).
This simplifies to 3y - 6 or 3(y - 2)
Since we don’t know what y is, this is as far as we can solve the problem.