Answer:
The lorry travels by 6 mph more than the expected speed.
Step-by-step explanation:
Velocity formula:
Velocity is distance divided by time, that is:
[tex]v = \frac{d}{t}[/tex]
Shortest route:
400 miles in 10 hours, which means that [tex]d = 400, v = 10[/tex]. So
[tex]v = \frac{d}{t} = \frac{400}{10} = 40[/tex]
In mph.
The lorry actually travels by a different route which increases the distance by 15%, but it still arrives in 10 hours.
Distance is multiplied by 100% + 15% = 115% = 1.15, so:
[tex]d = 1.15*400 = 460[/tex]
Then
[tex]v = \frac{d}{t} = \frac{460}{10} = 46[/tex]
46 mph
By how many more mph than the expected speed does the lorry travel?
46 - 40 = 6 mph
The lorry travels by 6 mph more than the expected speed.