On your first day as an apprentice at the oil refinery, you are asked to create usable graphs and tables for the other workers who fill the oil tankers.

You are given the following information to assist you with your assigned task at the oil refinery:

An oil tanker holds approximately 1,785,000 gallons of petroleum product. The refinery has two hoses that can be used to fill a tanker, a large one and a small one. On an average day, it takes 20 hours to fill an empty tank with the largest hose and 30 hours with the smallest hose.

Determine the constant rate of change in the hold of the tanker for each hose.