DAY 70

Comment

The way the story is worded, it might appear that the hare never quite catches up with the tortoise, never mind rushes past at ten times the tortoise's speed. This is because the focus is on ever shorter time intervals preceding the moment at which the hare catches up with the tortoise.

Answer

The hare catches up with the tortoise after running 1111/9 metres (111.1111... metres).

Readers' methods

B Blount, Keynsham:
One tenth of 100 is 10.
One tenth of 10 is 1.
One tenth of 1 is 1/10 or 0.1.
One tenth of 0.1 is 1/100 or 0.01.
One tenth of 0.01 is 1/1000 or 0.001, and so on.
So the hare runs 111.111111111... metres.

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