Question

A telephone long distance carrier charges customers $0.99 for the first 10 minutes and then $0.04 for each minute beyond 10 minutes. If Mary uses this carrier, how long can she talk for $4.00

Answer 1

4.00 - 0.99 = 4.01 will give 10 minutes.

4.01 divided by 0.04 minutes = 100.25.

This can be expressed as:

10 + 100.25 minutes = 110,25 minutes , so Mary can talk for 110.25 minutes.