Feel in the blanks with the most accurate statement. $($If for one part you know the exact solution, then put the same number for at

least and at most. For instance, if your answer is exactly $2100,$ then put at least $2100$ and at most $2100.)$

We have a network of pipes through which we are sending a maximum flow. The current value of maximum flow is $1000.$ Two of these pipes,

with capacities $70$ and $90$ break. The new maximum flow will be at least

and at most

Consider the previous setting. Only this time, we know that the pipe with capacity $70$ is going from some node A to node B$,$ and the pipe with

capacity $90$ goes from $B$ to $C.$ The new maximum flow will be at leas

and at most

In another network, we are shipping some products through a network using a minimum$-$cost flow model. The current optimal minimum$-$cost

flow has a cost of $$2500.$ As a result of a change in management, the cost of a certain shipping link with capacity $30$ has gone from $$\frac{10}{u}$nit

to $$\frac{15}{?}$ unit. The new optimal minimum$-$cost flow will be at least

and at most