Answer:
75 mph
Step-by-step explanation:
A biker must circle a 12-mile track twice. His average speed must be 60 mph.
So, the average time required to cover the distance is [tex]\frac{2 \times 12}{60} = 0.4[/tex] hours.
Now, on his first lap, he averaged 50 mph.
So, he covered this 12 miles track in [tex]\frac{12}{50} = 0.24[/tex] hours.
Hence, he has to cover the next 12 miles track in (0.4 - 0.24) = 0.16 hours.
Therefore, his average speed in the second round must be [tex]\frac{12}{0.16} = 75[/tex] mph to qualify. (Answer)
