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Two trains brainteaser

By David Shaw, 29 June 2022

Difficulty: Fun

A fast passenger train leaves Sydney Central station, headed for Broken Hill. At the same time, a slow freight train, moving at only half the speed of the passenger train, leaves Broken Hill station, headed for Sydney Central.

When they meet, which train is closer to Sydney?

Here are some numbers, in case you need them:

• The fast passenger train travels at 100 kilometres per hour.
• The slow freight train travels at 50 kilometres per hour.
• Both trains leave at midday.
• The distance from Broken Hill to Sydney Central is 900 kilometres.

 
Scroll down or click for a hint, or the answer!

 

Brainteaser hint

You don’t need any of the numbers to answer the question. Ask yourself, where is the fast train when the trains meet? How about the slow train?

Brainteaser answer

When the 2 trains meet, the fronts of each train are the same distance from Sydney! The back of the fast passenger train is slightly closer to Sydney, and the back of the slow freight train is slightly further away.

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