Jane's cell phone plan is $40 a month plus $0.15 per minute for each minute over 200 minutes. If Jane's cell phone bill Is $58.00, for how many extra calling minutes was she billed?

Answer: she was billed for 120 extra minutes.

Step-by-step explanation:

Let x represent the total number of minutes that Jane used.

Jane's cell phone plan is $40 a month plus $0.15 per minute for each minute over 200 minutes. Thus means that the total cost for x minutes on the phone would be

40 + 0.15 (x - 200)

40 + 0.15x - 30

0.15x + 40 - 30

0.15x + 10

If Jane's cell phone bill Is $58.00, it means that

0.15x + 10 = 58

0.15x = 58 - 10 = 48

x = 48/0.15 = 320

The total number of minutes that she used is 320.

The total number of extra minutes for which she was billed is

320 - 200 = 120