The parent chain and the numbers are marked in red on the image.
Work Step by Step
1. Find the parent chain. In this case, the rule is: - It has to be as large as possible. 2. Identify where you are supposed to start counting. In this case, it doesn't matter. If we count the numbers from the left, the substitutents (ethyl and methyl) will get 2 and 4. If we count the numbers from the right, the substitutents (ethyl and methyl) will get 2 and 4 too. Since there is no minimum one, you can pick anyone.