Respuesta :

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

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