Question: daisy has a busy social and work life and uses...
Daisy has a busy social and work life and uses her mobile phone to stay in contact. She is trying to compare mobile phone providers to find the most cost effective option for her.
Phones’R’Us offer a $40 per month plan. This includes 15 000 free SMS within Australia. For each SMS over 15 000, Phones’R’Us then charge a flat rate of 0.1 cents per SMS.
Text’4’Cheap charge 0.35 cents per SMS but have no monthly costs.
a) On the graph paper provided, on the same set of axes, draw graphs which show the monthly spend for Phones’R’Us and Text’$’Cheap for users who spend between 0 and 20 000 SMS’s per month. Hint: make the number of SMS and the monthly spend.
b) Equations in the form of can be used to represent these mobile phone plans.
(i) Write an equation to represent the Text’4’Cheap mobile phone plan.