20. A woman ran a 24-mile course. She ran the first 6 miles in 1 hour, the second set of 6 miles in 1.2 hours, the third set of 6 miles in 1.5 hours, and the fourth set of 6 miles in 1.6 hours. How long did it take her to complete the course?
Answer: A
It took her 5.3 hours to complete the course.
To determine the total time taken by the woman to run the 24-mile course, we must add the time for each segment. The total time is calculated as 1 hour + 1.2 hours + 1.5 hours + 1.6 hours, which equals 5.3 hours.
A) 5.3 hours
This option is correct as it accurately sums the time taken for each segment of the run: 1 hour for the first 6 miles, 1.2 hours for the second 6 miles, 1.5 hours for the third 6 miles, and 1.6 hours for the final 6 miles, totaling 5.3 hours.
B) 5.4 hours
This option is incorrect because it slightly overestimates the total time. The correct summation of the segments does not reach 5.4 hours, indicating a miscalculation in adding the individual times.
C) 4 hours
This option is incorrect as it underestimates the total time. Adding the segment times clearly exceeds 4 hours, showing that this option does not reflect the actual duration taken for the entire course.
D) 5 hours
This option is also incorrect as it falls short of the actual total time. The cumulative time of 5.3 hours is greater than 5 hours, thus making this option inaccurate based on the calculations presented.
Conclusion
The correct answer is 5.3 hours, as it is derived from the accurate addition of the time segments for each part of the run. All other options fail to represent the true total time, either by underestimating or overestimating the overall duration required to complete the course.