Chandrika was practising a long distance run she was going to do
In the first 10 minutes she ran well over 2 kilometres.
In the second 10 minutes she jogged just half that distance.
In the third 10 minutes she walked just half as far.
In the fourth 10 minutes she dawdled only half of that and so on.
Well, in theory at least, she would never have quite reached the end, but it happened that right at the end of a 10 minute stretch, exactly one metre from the finishing post, Chandrika tripped and fell forward over the line.