40 mins
40 = 0.667 hours
30 mins
30 = 0.5 hours
20 mins
20 = 0.3
15 mins
15 mins = 0.25 hours
When you have minutes but need hours for the question
40 minutes is 40/60 = 2/3 = 0.666.. hours
Therefore, the journey time is
5 + 0.666… = 5.666. . . hours