SOLUTION: I need help to assist my 7th grader. How to set up ratio.... Phone Plan 1 is $.18 per minute Phone Plan 2 is $50 base plan and $.10 per minute. At what point is it cheape

Question 357055: I need help to assist my 7th grader.
How to set up ratio....
Phone Plan 1 is $.18 per minute
Phone Plan 2 is $50 base plan and $.10 per minute.
At what point is it cheaper to use plan 1?
How do I show her how to do this?
Answer by nerdybill(7384) (Show Source): You can put this solution on YOUR website!
Let m = minutes used
.
Phone Plan 1 is $.18 per minute
cost of plan 1 = .18m
.
Phone Plan 2 is $50 base plan and $.10 per minute.
cost of plan 2 = .10m + 50
.
At what point is it cheaper to use plan 1?
"cost of plan 1" < "cost of plan 2"
.18m < .10m + 50
subtracting .10m from both sides:
.08m < 50
dividing both sides by .08
m < 50/.08
m < 625 minutes
.
Therefore:
At what point is it cheaper to use plan 1?
when minutes used is less than 625 minutes
RELATED QUESTIONS
Kim switched cell phone plans. She signed up for a new plan that saves her $3.50 per... (answered by Fombitz)

"A person buys a phone for $86 and signs up for a single-line phone plan with 2000... (answered by jim_thompson5910)

Kim switched cell phone plans. She signed up for a new plan that saves her $3.50 per... (answered by Cromlix)

Your parents have decided to get you a phone plan. You have to do some math to determine... (answered by fractalier)

Hi! I have to write a linear function of the monthly price of a cell phone plan, with x... (answered by ankor@dixie-net.com)

Hello, I was wondering if the formula I plan on using works with this problem; and if... (answered by MathLover1)

You have two options, to buy a cell phone plan or pay as you go. Ignore the cost of the... (answered by dfrazzetto)

My cell phone plan is $29.95 per month plus $.10 per minute for each minute over 300... (answered by richwmiller)

The cell phone company also has two texting plans. The first is unlimited texts for $12.... (answered by fcabanski)