\documentclass{standalone}

%\usepackage[a4paper, margin=25mm]{geometry}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}

\usepackage{xcolor}
\usepackage{tikz}
\usetikzlibrary{arrows,arrows.meta,bending,shapes,calc,intersections,positioning}

\definecolor{darkgreen}{rgb}{0.0, 0.45, 0.0}
\definecolor{darkblue}{rgb}{0.0, 0.0, 0.8}

\begin{document}
	
% Exercise 4	
	
\tikzstyle{2col}=[circle, draw=blue,dash pattern=on pi*1em off pi*0.9em,
	postaction={draw=orange,dash phase=pi*1em},
	,line width=.5mm,minimum size=1em]
	\begin{tikzpicture}
		\def\r{2}
		%nodes
		\node[2col] at (90:\r) (1) {$v_1$};
		\node[2col] (2) at (162:\r) {$v_2$};
		\node[circle, draw=orange, line width=.5mm,minimum size=1em] (3) at (234:\r) {$v_3$};
		\node[2col] (4) at (306:\r) {$v_4$};
		\node[circle, draw=blue, line width=.5mm,minimum size=1em] (5) at (18:\r) {$v_5$};
		%edges
		\draw (1) -- node[left, pos=.3] {\footnotesize $20,30$} (2);
		\draw (1) -- node[right, pos=.6] {\footnotesize $12,15$} (3);
		\draw (1) -- node[left, pos=.9] {\footnotesize $20,28$} (4);
		\draw (1) -- node[right, pos=.3] {\footnotesize $35,40$} (5);
		\draw (2) -- node[left, midway] {\footnotesize $25,40$} (3);
		\draw (2) -- node[below, pos=.85] {\footnotesize $40,45$} (5);
		\draw (3) -- node[below, midway] {\footnotesize $10,15$} (4);
		\draw (4) -- node[right, midway] {\footnotesize $15,30$} (5);
	\end{tikzpicture}


\end{document}