There is a ring road connecting points A, B, C and D. The road is in a complete circular form but having several approach roads leading to the centre. Exactly in the centre of the ring road there is a tree which is 20 km from point A on the circular road. You have taken around the circular road starting from point A and finishing at the same point after touching the other three points. You then drive 20 km interior towards the tree from point A and from there reach somewhere in between B and C on the ring road. How much distance do you have to travel from the tree to reach the point between points B and C on the ring road?
Why do we believe that in all matters the odd numbers are more powerful?
Pliny the Elder, Natural History
Students attend our lectures, not because the mathematics we teach ‘makes lots of fun’ for us, but because they believe they can learn some essential knowledge from us. And each of our young students has only one life to live. We should therefore be a