Question

For his phone service, Jose pays a monthly fee of $30, and he pays an additional $0.05 per minute of use. The least he has been charged in a month is $99.75.

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

Answer 1

He has used 1395 or more minutes each month.

Explanation:

Each minute cost $0.05.

m minutes cost 0.05m.

The monthly fee is $30.

The total monthly charge for the monthly fee and minutes is

0.05m + 30

His smallest charge was $99.75, so all his charges are $99.75 or more.

That means his charges are greater than or equal to $99.75.

0.05m + 30 ≥ 99.75

0.05m ≥ 69.75

m ≥ 1395

Answer: He has used 1395 or more minutes each month.