Asked by jack
It took a faster runner 10 sec. longer to run a distance of 1500 m than it took a slower runner to run a distance of 1000 m.If the rate of the faster runner was 5 m/sec more than the rate of the slower runner,what was rate of each?
Answers
Answered by
drwls
Let V be the speed of the slower runner. Let his (or her) time to run 1000 m be T. The faster runner's speed is V + 5 (in meters per second). Here is what you know:
(V+5)(T+10) = 1500
V*T = 1000
V*T + 5T + 10V + 50 = 1500
5T + 10V = 450
5000/V + 10V = 450 (after substituting 1000 for V*T)
V^2 -45V + 500 = 0
(after multiplying boith sidesw by V and dividing by 10)
(V-25)(V-20) = 0
V = 20 m/s, V+5 = 25 m/s, T = 50s would be one answer
V = 25 m/s, V+5 = 30; T = 40 s would be another answer.
It sounds fishy to me that there are two possible sets of answers. The speeds are also faster than humans can run.
(V+5)(T+10) = 1500
V*T = 1000
V*T + 5T + 10V + 50 = 1500
5T + 10V = 450
5000/V + 10V = 450 (after substituting 1000 for V*T)
V^2 -45V + 500 = 0
(after multiplying boith sidesw by V and dividing by 10)
(V-25)(V-20) = 0
V = 20 m/s, V+5 = 25 m/s, T = 50s would be one answer
V = 25 m/s, V+5 = 30; T = 40 s would be another answer.
It sounds fishy to me that there are two possible sets of answers. The speeds are also faster than humans can run.
There are no AI answers yet. The ability to request AI answers is coming soon!