Question 1084897
d=rt 
distance:
first part:2*7.5 = 15 km
sec. part 56*0 = 0km
third part 2*7.5 = 15 km

total distance 30km 
total time 60 mins
total speed = 30/60 = 1/2 km/h

i would love to hear alternative solutions from you 
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