Find out how many calls must be made to make Plan A the better deal.
• Plan A: $45 a month for unlimited calling Plan B $15 a month .10 per min.
I need to write a cost equation for plan A and for plan B then I need to solve.
Plan A: cost = 45
Plan B: cost = .10x + 15, where x is the number of minutes
You want to know when
.10x + 15 > 45
x + 150 > 450
x > 300
check:
for 299 minutes:
PlanA = 45
PlanB = 29.90 + 15 = 44.90
...... Plan B is still better
for 301 minutes:
Plan a = 45
PlanB = 30.10 + 15 = 45.10
.... Plan A is better for x > 300
To find out how many calls must be made to make Plan A the better deal, you need to compare the costs of both Plan A and Plan B and find the point at which Plan A becomes cheaper.
First, let's write the cost equation for Plan A. Plan A costs a fixed amount of $45 per month, regardless of how many calls are made. So the cost equation for Plan A is:
Cost(A) = $45
Now let's write the cost equation for Plan B. Plan B costs $15 per month, but there is an additional charge of $0.10 per minute for each call. So the cost equation for Plan B can be written as:
Cost(B) = $15 + $0.10 * (number of minutes)
To find out when Plan A becomes the better deal, we want to compare the costs of Plan A and Plan B. We can set up an inequality:
Cost(A) < Cost(B)
Substituting the cost equations, we can write:
$45 < $15 + $0.10 * (number of minutes)
Now we can solve for the number of minutes needed to make Plan A the better deal:
$45 < $15 + $0.10 * number of minutes
Subtracting $15 from both sides:
$30 < $0.10 * number of minutes
Dividing both sides by $0.10:
$300 < number of minutes
So, to make Plan A the better deal, you would need to make more than 300 minutes of calls.