Mathematical Modeling Questions for Secondary School Curriculum | Page 15

Mobile phone companies

Author : Mihaela Git
Two different mobile phone companies announced their subscriptions ’ offers . The first one ’ s is about 9 € per month and it has 900 minutes and every extra minute means 30 cents more to pay . The second one ’ s should be paid 12 € per month for 400 included minutes and calling is billed with 0,20 Euro per minute .
a )
Which of these companies have the most efficient offer , for the needs of a
person that works in business ?
b )
Define the functions that express the cost variation per number of minutes .
c )
Represent the plots of the two functions in the same coordinate system .
Related Topics and Concepts : Functions , graphs Real Life Context : Economy , Price policy