Problema Solution

When roadwork begins, the current speed limit will be decreased by 40km/h. It will take at least 3.6 hours to cover the same distance that would be covered in 2 hours now. What is the speed limit now?

Answer provided by our tutors

let


v = 40 km/h the rate of the work


t = 2 hr


d = the distance that will be covered in 2 hours


since v = d/t follows d = v*t that is:


d = 40*2


d = 80 km


it will take at least 3.6 hours to cover the 80 km distance thus the speed limit is:


80/3.6 = 22.22 km/h.