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Speed over a Bridge

Age 11 to 14 Short
Challenge Level

A train that is 100 metres long is travelling at a constant speed. It takes 30 seconds to clear a bridge which is 400 metres long.

What speed is the train travelling at, in kilometres per hour?


This problem is adapted from the World Mathematics Championships
You can find more short problems, arranged by curriculum topic, in our short problems collection.
The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.
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