19. An athlete runs 4 miles in 28 minutes and then changes pace to run the next 4 miles in 32 minutes. Overall, what is the average time in minutes it takes the athlete to run 1 mile?
Answer: A
The average time it takes the athlete to run 1 mile is 7.5 minutes.
To find the average time per mile, we first calculate the total time taken for the entire 8 miles. The athlete runs the first 4 miles in 28 minutes and the next 4 miles in 32 minutes, resulting in a total time of 60 minutes for 8 miles.
A) 7.5 minutes
This option is correct as it is derived from the calculation of total time divided by total distance. The total time is 60 minutes for 8 miles, leading to an average of 60 minutes / 8 miles = 7.5 minutes per mile.
B) 7 minutes
This option is incorrect because it underestimates the average time per mile. Given the total time of 60 minutes for 8 miles, 7 minutes per mile would total only 56 minutes, which does not match the actual time taken.
C) 8.5 minutes
This option is also incorrect as it overestimates the average time per mile. If the average were 8.5 minutes, the total time for 8 miles would be 68 minutes, which exceeds the actual time spent running.
D) 8 minutes
This option is incorrect because it similarly overestimates the average time. An average of 8 minutes per mile would result in a total of 64 minutes for 8 miles, which again does not align with the actual 60 minutes taken.
Conclusion
The correct answer of 7.5 minutes accurately reflects the average time per mile based on the total time of 60 minutes for 8 miles. All other options fail to represent the correct calculation and lead to totals that either underestimate or overestimate the actual time taken by the athlete.