A freight company will move one truck load of material according to the following cost schedule: The base shipping fee is $400 for any distance up to and including 150 miles and an additional $50 for each 50 mile increment over 150 miles.

Question

The cargo cost is 15 cents per pound of freight shipped
The total shipping cost is the sum of the base shipping fee and the cargo cost
In the context of the scenario above, suppose you need to ship 3000 lbs. discuss the continuity of the total cost as a function of the trip distance for total distances ranging from 50 to 350 miles. Then, for trips less than 150 miles, discuss the continuity of the total cost as a function of shipping weight for total freight weighing 1000 to 4000 lbs. What are the roles played by limits in analyzing the continuity of each function in your answers?
For the first part is the function 0<x < or = 1<0
For the second part is the function 1000 < or equal to x < or equal to 4000
What is the limit I can’t figure it out for both parts. Any help would be greatly appreciated.