Puzzle 2

718

04 Jan 10 21:17

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Date Joined: 08 May 08

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Puzzle 2

A long train, half a kilometre long, is about to enter a long tunnel. The tunnel is 10km long. If the speed of the train is 35kph, how long will it take for the entire train to pass through the tunnel - from the front of the train entering to the end of the train leaving the tunnel?

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Report a bitofinterest • January 4, 2010 9:19 PM GMT

that would depend on cargo velocity etc etc

Report garlicbread • January 4, 2010 9:20 PM GMT

18 mins 51 seconds

Report 718 • January 4, 2010 9:22 PM GMT

Almost. I think this forum may be brighter than I gave it credit for :(

Report Reyes • January 4, 2010 9:23 PM GMT

is it a eurostar train? about 10 hours?

Report a bitofinterest • January 4, 2010 9:23 PM GMT

im obviously smarter than i look

Report Ibrahima Sonko • January 4, 2010 9:24 PM GMT

20 seconds

Report garlicbread • January 4, 2010 9:24 PM GMT

Well 18 mins 51.4 seconds then

Report FatherMaguire • January 4, 2010 9:33 PM GMT

I might be having a thick day but I get 18 minutes... - can you provide workings out with solution

Report garlicbread • January 4, 2010 9:34 PM GMT

I make the train 1 km long, and it takes 18 mins 51 seconds to travel 11km at 35kph.

Report SuperSuperShire • January 4, 2010 9:34 PM GMT

18 mins

Report SuperSuperShire • January 4, 2010 9:36 PM GMT

front of the train has to travel 10k to leave the tunnel, and then a further 0.5k until the end of the train has left the tunnel. so a total of 10.5k. Which takes 60 x (10.5/35) = 18 minutes.

Report 718 • January 4, 2010 9:36 PM GMT

Spot on

Report garlicbread • January 4, 2010 9:37 PM GMT

Surely the front entering to the end leaving makes 1km?

Puzzle 2

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