The "Frog"

A scientist has a frog a tells it to jump. It jumps 20 feet. He cuts of a
leg then tells it to hop, it then hops 15 feet. He again cuts off a leg
and again tells it to hop, this time it hops 10 feet.  Then he cuts off
another leg and tells it to hop, it hops 5 feet.
He then cuts off the last leg and tells it to hop.
HOP! HOP! HOP! he says, the frog will not hop.

He records all of his findings in his log book: 4 legs 20ft, 3 legs
15ft,2 legs 10ft, 1 leg 5ft, 0 legs FROG DEAF!