Final answer:
The equation for Company A's total cost (C) in terms of hours (age) when they charge $40 per hour is C = 40 * age. This relationship is linear and the formula accounts for the total cost increasing proportionally with the number of hours worked.
Step-by-step explanation:
The question asks to determine Company A's total cost (C) equation in terms of the number of hours (age) given their hourly rate. Since Company A charges $40 per hour and there are no additional one-time charges mentioned, the total cost will be directly proportional to the amount of time worked. Therefore, for each hour worked, the cost increases by $40.
To express this mathematically, we can create a linear equation. Let age represent the number of hours worked. The total cost (C) is calculated by multiplying the hourly rate ($40) by the number of hours (age), which gives us:
C = 40 * age
This formula dictates that for every additional hour of age, there is an additional cost of $40. This is a linear relationship with no fixed cost (overhead).