Thousands at one time.
Goldfish do lay eggs. The eggs will attach to something in the tank or bowl until they hatch.
15 - 20
when you get it a mate.
Goldfish normally spawn once yearly in Spring time.
Goldfish are egg layers
Yes. Laying eggs is how they reproduce.
Yes.
Yes.
yes
yes they can!
goldfish need to lay eggs. Because if they don't no goldfish would be alive and would not be any more so they would become gone forever.