What are the two ways that an amendment be proposed and ratified?

Answer 1

1. Introduced in Congress, passed by 2/3 of each House, ratified by 3/4 of the states.

2. Introduced at a Constitutional Convention, passed (there is no clearcut number needed as defined by Article V of the Constitution), and then ratified by 3/4 of the states. Congress must call for a convention if 2/3 of the states' legislatures apply to Congress for such a convention.