Stochastic Consistency Test

Here are 5 jokes:

1. The Software Developer Why did the developer go broke? Because he used up all his cache.

2. The Tree What did the big flower say to the little flower? "Hi, bud!"

3. The Boat Why was the math book sad on the boat? It had too many problems.

4. The Elevator I used to play piano by ear, but now I use my hands. (This is a play on words: "play by ear" usually means improvising, but here it implies using physical ears to play, which is impossible, so the correction implies the listener misunderstood.)

5. The Cheetah Why don't cheetahs win at hide and seek? Because they're always spotted.

How many are unique? 5 (They are all unique jokes).