Question

For her phone service, Charmaine pays a monthly fee of $15, and she pays an additional $0.05 per minute of use. The least she has been charged in a month is

$66.90.
What are the possible numbers of minutes she has used her phone in a month?
Use m for the number of minutes, and solve your inequality for m.

Answer 1

Explanation:

after subtracting the monthly fee (which she has to pay, even if she does not make a single call) we have

66.9 - 15 = $51.90

for actual phone call minutes.

1 minute is $0.05

so, in the month with the lowest charge she had used

51.9 / 0.05 = 1038 minutes for calls.

since this was the minimum, for all the numbers of minutes m she used in a month we have

m >= 1038 minutes