help pls!!!?

Question

i tried this but i dint get it.
dan goes from station A to station B at the speed of 40 km/hr and returns from station B to station A at the speed of 60 km/hr. find his average speed for the whole journey.
ans=180m

hint: the average speed = total distance/ total time.

Answer 1

Average may be refer to the statistical mean, medium and mode.

There are two speeds.

going from A to B = 40km/hr

Returns from B to A = 60Km/hr

Add

40 + 60 = 100

Divide 100 ny 2 to obtain the average speed

100 / 2 = 50 km/hr

The answer is: The average speed is 50km/hr

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Click on the URL below for additional information concerning Average.

en.wiktionary.org/wiki/average

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Answer 2

Assume that the distance from A to B is 60 kms. If he travels at 40 kms/hr the first time (A to B) he will reach B in 90 minutes. On the way back he will reach A in 60 minutes, for a total of 150 minutes. So, he has traveled 120 kms in 150 minutes, or 48 kms/hr.

Answer 3

Assume distance to be x. the time taken from A to B is x/40 hours and on his return the time taken is x/60 hours. total time taken is x/40 + x/60 = 1/24 X hours. Total distance travelled is 2x.

AVerage spped is = 2x divided 1/24x = 48Km/ hour.

Answer is incorrect as the average can only be between 40 and 60 Km/hour. 180 is incorrect.

Answer 4

LET average speed be V
total distance = 2s
total time = t
time for forward journey= t1= s/40
time for return journey = t2 = s/60

so average speed = V = 2s/(t1+t2)

=2s/(s/40 + s/60)

= 2/(1/40 + 1/60)

= 48 Km/hr

Answer 5

Am I missing something? Isn't it simply 50 km/hr. Distance is the same both ways so, it doesn't factor in.

Answer 6

Curt, I think it has something to do with the fact that when hes going slower then hes taking longer so hes actually going at a slower speed for longer than he is traveling at a faster speed for a shorter amount of time.

I think