Answer:
Average speed = 90 km/h
Step-by-step explanation:
Given that:
Distance covered at 100 km/h = 450 km
Time = [tex]\frac{Distance}{Speed}[/tex]
Time = [tex]\frac{450}{100}=4.5\ hours[/tex]
Distance covered at 60 km/h = 90 km
Time = [tex]\frac{90}{60}=1.5\ hours[/tex]
Total distance travelled = 450 + 90 = 540 km
Total time taken = 4.5 + 1.5 = 6 hours
Average speed = [tex]\frac{Total\ distance}{Total\ time}[/tex]
Average speed = [tex]\frac{540}{6}[/tex]
Average speed = 90 km/hr
Hence,
Average speed = 90 km/h
