Answer:
12
Explanation:
avarage speed = total distance/total time
our total distance is 40km
the first 20km speed was 20km/h, so the time os 1 hour here
for the next 20km, we dont have the time, so let the time here be = x
so total time is x+1 km/h
and total distance is 40km
and the avarage is 24km/h
so =>
[tex] \frac{40}{1 + x} = 24[/tex]
solve for x to find the time in the second 20km
so x=0.6
then find the speed of the second 20km by diving the distance on time =>
[tex] \frac{20}{0.6} = 12[/tex]
so the speed in the second 20km is 12km/h
