Question

2 i am travelling to see a friend this weekend. my trip will consist of a 105km journey along the motorway, followed by a crossing on a ferry which takes 30 minutes and then a further 10km along smaller roads to my friends house. i can drive at 70km/h on the motorway, but at only 40km/h once i reach the smaller roads. i have booked my crossing for 14:00 and have told my friend that i will arrive at 15:30. what is the latest time that i could leave home for my journey? 2

Explanation:

Step1: Calculate motorway travel time

Time = $\frac{\text{Distance}}{\text{Speed}} = \frac{105}{70} = 1.5$ hours = 1 hour 30 minutes

Step2: Calculate small roads travel time

Time = $\frac{\text{Distance}}{\text{Speed}} = \frac{10}{40} = 0.25$ hours = 15 minutes

Step3: Sum all journey segments time

Total time = 1h30m + 30m + 15m = 2 hours 15 minutes

Step4: Subtract total time from arrival

15:30 - 2h15m = 13:15

Answer:

13:15