Palmer's average running speed is 4 kilometers per hour faster than his walking speed. If Palmer can run around a 40-kilometer course in 4 hours, how many hours would it take for Palmer to walk the same course? (Round your answer to two decimal places.)
A) 7.75 h
B) 5.59 h
C) 6.67 h
D) 11.53 h
E) 7.21 h

Question

Quizplus · Accepted Answer

Let's say the walking speed is "x" kilometers per hour. 
According to the problem, the running speed is 4 kilometers per hour faster than the walking speed. Therefore, the running speed would be x+4 kilometers per hour.
We know that he completes a 40-kilometer course in 4 hours when running.
Speed = distance/time
Therefore, his running speed would be 40/4 = 10 kilometers per hour. 
Now we can set up an equation based on the information given:
x+4 = 10
x = 6
This means his walking speed is 6 kilometers per hour.
We can now use the equation again to calculate the time it would take him to walk the 40-kilometer course:
Speed = distance/time
6 = 40/time
time = 40/6
time = 6.67 hours
Therefore, it would take Palmer 6.67 hours to walk the same course. Rounded to two decimal places, the answer is 6.67. So, the correct choice is C.

Palmer's Average Running Speed Is 4 Kilometers Per Hour Faster