Question

A phone company offers two monthly plans. Plan A costs $27 plus an additional $0.15 for each minute of calls. Plan B has no initial fee but costs $0.19 for each minute of calls.

For what amount of calling do the two plans cost the same?

What is the cost when the two plans cost the same?

Answer 1

Let's denote the amount of calling time by "x".

For Plan A, the monthly cost would be $27 plus $0.15 per minute, so the total cost would be:

C(A) = 27 + 0.15x

For Plan B, the cost per minute is $0.19, so the total cost would be:

C(B) = 0.19x

We want to find the amount of calling time "x" for which the two plans cost the same, so we can set the two equations equal to each other and solve for "x":

27 + 0.15x = 0.19x

27 = 0.04x

x = 675

Therefore, when the amount of calling time is 675 minutes, the two plans cost the same.

To find the cost at this amount of calling time, we can substitute x = 675 into either equation:

C(A) = 27 + 0.15(675) = $121.25

C(B) = 0.19(675) = $128.25

So, at 675 minutes of calling, both plans cost the same amount, which is $121.25.