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On the Road

Four vehicles travelled on a road. What can you deduce from the times that they met?

There and Back

Brian swims at twice the speed that a river is flowing, downstream from one moored boat to another and back again, taking 12 minutes altogether. How long would it have taken him in still water?

Escalator

At Holborn underground station there is a very long escalator. Two people are in a hurry and so climb the escalator as it is moving upwards, thus adding their speed to that of the moving steps. ... How many steps are there on the escalator?

Speeding Boats

Age 14 to 16
Challenge Level

Below are two diagrams which show ways of thinking about the problem when one boat travels twice as fast as the other. Can you make sense of them? Do you have your own different way of seeing it?



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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