SOLUTION: Two travelers in a train wanted to measure the speed of train. First one counted the number of "clicks" (sound to be heard when train passes track). He counted 156 clicks, and the

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Question 835728: Two travelers in a train wanted to measure the speed of train. First one counted the number of "clicks" (sound to be heard when train passes track). He counted 156 clicks, and the distance between two clicks is 10 meters. He measured (counted) for 3 minutes, stopped the watch and the result was 31,2 km/h.
Second passenger counted the poles by the railroad. Distance between the each pole was 50 meters and he counted 32 poles per 3 minutes. The result was 32 km/h.
So, which one of them was right and why?
I tried and checked both ways in a usual manner:
1. 156 x 10 / 180 = 8,66 etc. x 3,6 = 31,2 km/h
2. 50 x 32 / 180 = 8,88 etc. x 3,6 = 32 km/h.
So, both of them were "right".
But, if I assume that the number of clicks counted for the first traveler should have been 160, then I get 160 x 10 / 180 = 8.88 x 3,6 = 32 km/h, the same result as it was for second guy.
But I don't know why should I have to put extra 4 clicks?
And which travelers got the right outcome, and why...?
Sorry about my English, I am from Montenegro, Europe.
Thank you in advance,

DRAGAN
draganche70@gmail.com
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Think about how each person is measuring.
The first person starts to measure when he hears the first click (distance=0) and stops measuring on the last click (distance=x).
If there were two clicks, x=10.
x=10%2A%28N-1%29 where N is the number of clicks.
x=10%2A%28156-1%29=1550 in 3 minutes.
R%5B1%5D=1550%2820%29%2F1000=31 km/h
Similarly, the second person counts the poles.
If she sees two poles, the distance is 50m.
y=50%28P-1%29, where P is the number of poles.
y=50%2832-1%29=50%2831%29=1550 in 3 minutes, same as the first.
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Don't worry about your English, je bilo dosta dobro. Sve najbolje!