[tex]\displaystyle \\
\texttt{Calculam numarul termenilor: } \\ \\
n= \frac{100-2}{2}+1 = \frac{98}{2}+1=49+1 = \boxed{50 ~de~termeni} \\ \\
\frac{2}{255} + \frac{4}{255} + \hdots + \frac{100}{255}= \frac{2+4+\hdots +100}{255}= \\ \\ \\
= \frac{ \dfrac{50(100+2)}{2}}{255}= \frac{25 \times 102}{255}=\frac{5^2 \times 2\times 51}{ 5 \times 51 } = 5 \times 2 = \boxed{\boxed{10} } [/tex]