Question

You have a choice two cell phone plans.

Plan A: 39.99 per month for 600 minutes plus .40 for additional minute
Plan B: $45 per month with unlimited minutes

How many minutes must you talk in one month to make plan B the best cell phone plan for you?

Answer 1

hint:
If I talk for \(N\) l minutes, in one month, then using plan A, I pay this:
\[\Large 39.99 + \left( {0.4 \times N} \right)\]
Plan B is the best plan if the subsequent condition holds:
\[\Large 39.99 + \left( {0.4 \times N} \right) > 45\]

Answer 2

oops.. \(N\) represents the number of additional minutes

Answer 3

Is .4 suppose to be .40? Thank you so much for helping me btw !!!

Answer 4

:)

Answer 5

yes! It is \($0.40\)

Answer 6

Is N 15?

Answer 7

I got \(N \simeq 13\)

Answer 8

Really? But why 13

Answer 9

here is why:
\[\Large \frac{{45 - 39.99}}{{0.40}} = 12.525 \simeq 13\]

Answer 10

please try to solve this equation for \(N\):
\[\Large 39.99 + \left( {0.4 \times N} \right) = 45\]

Answer 11

Sorry I'm so confused?! What's the first step I have to solve?

Answer 12

I'm Trying to write everything down in order

Answer 13

as first step, you have to solve this equation:
\[\Large 39.99 + \left( {0.4 \times N} \right) = 45\]
please find \(N\)

Answer 14

To find N I have to subtract 45 with 39 right?

Answer 15

that's right!
\(45-39.99=...?\)

Answer 16

5.01!! :)

Answer 17

now, please divide by \(0.40\)

Answer 18

12.525

Answer 19

correct!
it means if I talk for at least 13 additional minutes the cost of Plan A is equal to the cost of Plan B
Whereas if I talk for additional 15 minutes or 14 minutes, then cost of Plan A is Greater than the cost of Plan B

Answer 20

Wait so 12.525 is minutes or cost.

Answer 21

Do we round ? How is 12.525 = 13 :0