The Ox King on Fire Mountain - Dragon Ball Episode 7 Reaction

At the time Dragonball was made Chi-chi was a slang term in Japanese . . . for breasts. The creator of the show didn't expect it to be popular so he kind of used it as a pun factory. Most the the characters have pun names and the story is full of cheeky humor and corny dad jokes.

To answer your question, Yamcha and Bulma are both 16, and Goku and Chi-Chi are both 12