6. Two cell phone companies charge a flat fee plus an added cost for each minute or part of a minute used. The cost is represent
ed by C and the number of minutes is represented by t. Call-More: C = 0.40t + 25 Talk-Now: C = 0.15t + 40
a) Which company is cheaper if a customer talks for 50 minutes. (1 mark)
b) Under what conditions do the two companies charge the same? (3 marks)
c) Under what conditions is Talk-Now better? Explain
The two companies would charge the same for 60 minutes of use.
Talk Now is cheaper the more minutes you talk. At some point the rate of change of Call More makes it more expensive. That point is just after their costs are even.
