Answer:
a.150
Step-by-step explanation:
We are given that a cell phone provider offers a plan that cots $30 per month plus $0.20 per text message sent or received.
A comparable plan costs $60 per month but offers unlimited text messaging.
a.If number of text messages sent or received =150
For I plan
Cost of one text message sent or received per month=$0.20
Cost of plan per month=$30
Costs of 150 text messages sent or received=[tex]0.20\times 150=$30[/tex]
Hence, total costs of plan I =$30+$30=$60
But in II plan no charge for text message and cost of plan per month is $60
Hence, the text messages 150 would have to be sent or received in order for the plans to cost the same each month.
b.If number of text messages =50
Then the cost of messages in plan I=[tex]02.0\times 50[/tex]=$10
Cost of plan I =$30
Total cost of plan I=30+10=$40
But in second plan no charge for text messaging and cost per month is $60.
Therefore, plan I is better than second plan.Because the cost of plan I is less than the cost of second plan per month.