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## 'Speedy Sidney' printed from http://nrich.maths.org/

Two trains set off at the same time from each end of a single
straight railway line which is 100 km long.

The first train travels at a constant speed of 55 km/h. The
second train travels at a constant speed of 70 km/h.

A very fast bee, Sidney travels at 100 km/h. Sidney starts off
in front of the first train and flies continuously back and forth
between the two trains.

How far does Sidney fly before he is squashed between the two
trains?

Extension:

How could you alter the problem so that Sidney flies exactly 100
km?

*(Apologies to bee lovers everywhere!)*