If you travel a distance of 100 miles
and the first half of the trip you go at 100 MPH
and the second half of the trip you go at 50 MPH
What is your average speed for the trip?
Simple math question for dum dums
by JH 103 Replies latest jw friends
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larc
66 2/3 mph
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Mary
75 miles per hour?
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Stan Conroy
66.666666 Mph
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JH
That's correct Larc
The first time I looked at that question, it looked so simple, so I said the average speed is 75 MPH.
The first half of the trip is 50 miles and going at 100 mph takes half an hour
The second half of the trip is 50 miles and going at 50 mph takes one hour.
So the total trip takes 1.5 hours
100 miles divided by 1.5 hours = 66.6 MPH
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Vivamus
How fast is one MPH? I calculate in Kilometers, can't do it otherwise.
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eyeslice
75 miles per hour
The total journey of 100 miles takes 1.1/3 hours
Half that time (i.e. 2 3rds of an hour) is spent travelling at 100 mph - distance = 66.66 miles
Half that time (i.e. 2 3rds of an hour) is spent travelling at 50 mph - distance = 33.33 miles
Total distance travelled = 75 miles divide by time in hours of 1.1/3 = 75 mph
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larc
eyeslice, as JH pointed out, the trip took 1.5 hours.
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eyeslice
Easy to be caught out here by the wording of the question.
The answers 66.66 mph and 75 mph could both be correct.
The difference is on the definition of the first half. I took it to be time, i.e. calculate the the total journey time. Or, it could be distance.
lesson - always clarify the question.
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eyeslice
larc,
As in most things in life things are never black and white.
Your journey took you 1.1/2 hours, mine took only 1.1/3 but we both travelled half at 100mph and a half at 50mph.
Problem we have is defining what the half is!
Given that we probably have both even greater arguements over religious beliefs that we once held with those who still cling to them, this is an object lesson in never being too dogmatic. We are both right in our way!!!!
regards
eyeslice