Mark: six times at 25 minutes
- times you get ready: 6
- minutes each time: 25
- last-minute changes: 2
- cost of one change: 40
- comparison limit: 3 hours
2.5 hours
6 × 25 = 150 minutes. 150 ÷ 60 = 2.5 hours. The 3-hour limit and the cost 2 × 40 = 80 appear in the results.