What can be said about the missing number in this serie?

Question

Tough puzzle this one, at least for me. I'm missing something and can't figure it out. I have the following sequences:

\begin{array}{cccc} 100 & 25 & 74 & 1 \\ 96 & 11 & 25 & 60 \\ 104 & 13 & 45 & x \end{array}

What can be said about $x$?

1. $40 \leq x < 50$
2. $x > 50$
3. $x \leq 40$

Answer 1

Note that $100 - 25 - 74 = 1$ and $96 - 11 - 25 = 60$. So I'd guess $104 - 13 - 45 = x$.