$1-(30$ pts$)$ Consider a $4-$node network $($with $0$ as the depot vertex and $3$ other vertices$)$ where the travel cost matrix and the demands are as follows:

$\backslash$table$[[,0,1,2,3,$Demand$],[0,0,25,55,40,-],[1,25,0,65,25,25],[2,55,65,0,60,30],[3,40,25,60,0,20]]$

Using a homogeneous fleet of vehicles with capacity $60$ :

$($Show the calculation and steps clearly and provide the routes and total length for both parts

a$)$ pts$.)$ Find the solution using the Insertion heuristic.