A cellular phone company offers two types of monthly plans.
Plan A: 10 cents per minute
Plan B: a monthly fee of $10 plus 7.5 cents/minute
Define the appropriate variables and write an equation relating the cost and the numbers of minutes for each plan.
X = The # of min. used.
C = Total cost.
Plan A: C = 0.1x.
Plan B: C = 0.075x + 10.
To define the appropriate variables, let's use the following:
- C: the total cost of the plan
- M: the number of minutes used
For Plan A, the cost per minute is 10 cents, so the equation representing the total cost for Plan A would be:
C(A) = 0.10M
For Plan B, the cost consists of a monthly fee of $10 plus 7.5 cents per minute. The equation representing the total cost for Plan B would be:
C(B) = 10 + 0.075M
In Plan B, the $10 monthly fee is constant regardless of the number of minutes used, but the 7.5 cents per minute would still vary based on M.