One evening . Gemma saw three different phone-company ads
. TeleTalk boasted a flat rate of 8€ per minute
. AmeriCall charges 30é per call
plus 5e per minute. Cel Time charges Ole per call plus caly 3c per minute.
a. Gemma is planning a phone call that will take about 5 minutes. Which phone plan should she use and how much will it cost?
b. Represent each phone plan with a table and a rule. Then graph each plan on the same set of axes, where a represents time in minutes
and y represents the cost of the call in cents. If possible
, use different colors to represent the different phone plans
.
c. How long would a call need to be to cost the same with TeleTalk and Americall
? What about AmeriCall and CellTime?
d. Analyze the different phone plans
. How long should a call be so that Americall is cheapest?