Stupid Scientist

There was this "not too bright" scientist doing a study on how frogs
respond to commands.

He tells a frog to jump. The frog jumps 30 feet. He writes in his log
book, frog jumps 30 feet.

Then he cuts off one leg. He gives the same command to frog. It jumps 25
feet. In Log: Cut off one leg, frog jumps 5 less feet.

He cuts off another leg. Frog goes 20 feet. He records it in log book.

Then he cuts off the 3rd leg, commands frog to jump. Frog jumps 10 feet.
He writes, cut off 3 legs and frog now jumps 10 less feet.

Finally, he cuts off the last leg and commands frog, JUMP! The Frog
doesn't move an inch.

So the scientist writes in his book... Cut off all 4 legs and frog GOES