Knowledge: The total number of humans living on this earth is impossible to know as not everyone registar to the government system. On the other hand, there are 500 different kinds of teas to enjoy.

Conversation:
I love tea. It is so good.
Oh do you!  Tea is made from an Asian evergreen shrub, called "Camellia sinensis." The leaves are cured, and once hot water is pour over them, the resulting beverage is aromatic.
I think earl gray is the best in my opinion.
Ah, really?  Oh did you know that after water, tea is the most consumed beverage?
Oh that's an interesting fact!  Can you tell me about the different types of tea?
There are so many types of different teas like Darjeeling, and Chinese greens. They have so many different flavors too.
I see. But I want to know in numbers. So what is the total number of different teas?

Response: Oh I see. The total number of different teas are 500.