i$,$ j $=1,2,...,7.$ We wish to develop a linear programming model to determine the route from the

storage facility to the job site that minimizes the total travel time.

$($a$)$ For the LP for the shortest route problem, write the supply $($node $1)$ constraint.

$($b$)$ For the LP for the shortest route problem, write the balance constraint for node $4.$

$($c$)$ For the LP for the shortest route problem, write the demand $($node $7)$ constraint.

You do not need to draw the network diagram, provide the complete LP formulation, or solve the

LP$.$