1: What is the source of a Saiyan's power?

2: Who created the original, and supremely powerful Dragon Balls?

3: When the evil scientist, Dr. Gero, first appears. Who does he show up as?

4: Who spots the evil androids first and what does the androids do to them?

5: What powerful technique do Goten and Trunks try to master in order to battle with the evil Super Buu?

6: In what year was Vegeta born?

7: How far can Goku's power pole extend?

8: During the time in the Hyperbolic Time Chamber. What was the move that Gotenks uses to damage Super Buu?

9: What was Yamcha's number one fear when he first met Goku?

10: How many students did Korin train through out the Dragon Ball saga?

1. They drew power from their tail, which is why they were weaker after having it removed.

2. Well, I'm not sure what the question entails. If you mean the first one to ever create dragon balls, I don't recall that ever being mentioned. If you mean the first to create them on Earth, it was the Nameless Namek (before he split into Kame and King Piccolo). Because he was more powerful than Kame (having not split into good and evil beings), his dragon didn't have the restrictions Kame's did. Those are the Black Star Dragon Balls. But I am sure that Guru made dragon balls before he did on the planet Namek, and those can be considered more powerful (based on your own opinions because it has different restrictions). 

3. Dr. Gero shows up as Android 20

4. Yamcha spots them first not knowing who they are. He tries to warn them, and Android 20 (Gero), grabs him by the mouth and begins draining his energy.

5. Fushion

6. Vegeta was born 732AD (in the show's timeline)

7. It can can extend all the way to the moon if the wielder wills it to, but it's main purpose was to be used to climb from Korin's tower to Kame's Lookout.

8. Super Ghost Kamikaze Attack

9. Yamcha was afraid of women

10. He trained Master Roshi, Goku, Krillin, Yamcha, Tien, Chiaotzu, and Yaijirobe, so that is 7. I can't recall anymore.