Explanation

The numbers t and so on could be 2, 4, 6, 8, 10, for example, though they could start at any even number. If we learn any one of the values, we'll be able to reconstruct the whole series, and that will be enough to calculate the average. If we learn the sum of all the numbers, that will give us the average of all of them. There may be other ways, too. Let's turn to the statements, separately first.

Statement (1) tells us that the average of u and v is 121. Since these are consecutive even integers, there is only one possible case: u must be 120 and v must be 122. That means we can determine the whole set of numbers and from it we can determine the average. Therefore, Statement (1) is sufficient.

Statement (2) tells us the sum of u and w. Since these are consecutive even integers, we already know a little something about how u and w are related: w must be u + 4. That means that this statement is telling us that . From this, we can solve for u (it's 120). That will allow us to determine the entire set of numbers and hence the average. Statement (2) is therefore sufficient.

The correct answer is (D).