Fifteen meters of rope for a twenty-meter drop. At first glance, the numbers do not add up.
The rope that falls short
Riddle statement
A climber is standing on a ledge 20 meters above the ground.
He has:
- a 15-meter rope;
- a knife;
- a secure anchor ring beside the ledge;
- another anchor ring exactly 10 meters below.
Beside the lower ring is a secure foothold from which he can handle and secure the rope.
Assume that he can cut, knot, manipulate, and descend on the rope safely, and that the length consumed by knots is negligible.
How can he reach the ground?