Maria called her sister long distance on Wednesday. The first 5 minutes cost $3, and each minute aft

Maria called her sister long distance on Wednesday. The first 5 minutes cost $3, and each minute after that cost $0.25. How much did it cost if they talked for 15 minutes?

First 5 minutes: $3

If they talked 15 minutes, the additional charge past 5 minutes is:
0.25 * (15 - 5)
0.25 * 10 minutes = $2.5

We add this to the first 5 minutes:
$3 + $2.5 = $5.50