The average speed of Martha and Sarah is 32 km/h.
We need to know about the speed to solve this problem. Speed can be determined as the distance traveled divided by time. It can be written as
v = s / t
where v is speed, s is distance and t is time.
From the question above, we know that:
t sarah = 3 hours
t martha = 5 hours
v sarah = 40 km/h
By using the speed equation, we get the distance
vsarah = s / tsarah
40 = s/3
s = 120 km
Find Martha's speed
vmartha = s / tmartha
vmartha = 120 / 5
vmartha = 24 km/h
Find average speed
v = (vsarah + vmartha)/2
v = (40 + 24) / 2
v = 32 km/h
Hence, the average speed of Martha and Sarah is 32 km/h.
Find more on speed at: brainly.com/question/6504879
#SPJ4
