Question 1182444: the track is a 500m circuit. Ali practices running at a speed of 10kph. Ben practices cycling and travels at 25kph. How long does Ali take to run one lap?
Found 5 solutions by mananth, greenestamps, ikleyn, CPhill, n2:
Answer by mananth(16949)   (Show Source):
You can put this solution on YOUR website! distance = 500m
speed = 10 kph
(10*1000)/3600 m/s ( 1 km = 1000 m, 1 hour = 3600 sec)
=2.7 m/s
t= d/s
500/2.7
= 185 seconds
Ali takes 185 s for a lap
Answer by greenestamps(13296)  (Show Source):
You can put this solution on YOUR website!
Another wrong answer from tutor @Mananth....!
She converted a fraction to an approximate decimal with only one decimal place, introducing a significant rounding error.
The track is 500m; the speed is 10km/hr = 10000m/hr.
Time is distance divided by speed:
(500m)/(10000m/hr) = 1/20 hr = 3 minutes
ANSWER: 3 minutes for a lap
Answer by ikleyn(53618)  (Show Source):
You can put this solution on YOUR website! .
the track is a 500m circuit. Ali practices running at a speed of 10kph. Ben practices cycling and travels at 25kph.
How long does Ali take to run one lap?
~~~~~~~~~~~~~~~~~~~~~~~~~
Calculations in the post by @mananth, giving the time 185 seconds, are inaccurate.
They do not provide the necessary precision.
I came to do the job properly.
Time(Ali) =  =  = 0.05 of an hour = 0.05*3600 = 5*36 = 180 seconds = 3 minutes.
ANSWER. Ali takes 180 seconds, or 3 minutes, for a lap.
Solved correctly, properly and accurately.
Answer by CPhill(2189)  (Show Source):
You can put this solution on YOUR website! distance = 500m
speed = 10 kph
(10*1000)/3600 m/s ( 1 km = 1000 m, 1 hour = 3600 sec)
=2.7 m/s
t= d/s
500/2.7
= 185 seconds
Ali takes 185 s for a lap
Answer by n2(54)  (Show Source):
You can put this solution on YOUR website! .
the track is a 500m circuit. Ali practices running at a speed of 10kph.
Ben practices cycling and travels at 25kph. How long does Ali take to run one lap?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Calculations in the post by @CPhill are incorrect.
He lost the necessary precision and came to wrong answer of 185 seconds.
The correct answer is 180 seconds, or 3 minutes,
as it is shown in correct solutions by @greenestamps and @ikleyn at this spot.
The error in 5 seconds is CATASTROFICAL for this problem.
I recommend to a reader to ignore the post by @CPhill.
|
|
|
