Which two of the world's major religions have india as their cultural hearth? explain which of those religions predominanates in india today and why that might be the case.

 Hinduism reached its fullest development in India , and spread into Southeast Asia before the advent of Christianity. It has not been widely disseminated. Hinduism has remained essentially a cultural religion of South Asia and is more than a faith; it is a way of life.
Buddhism, with fewer than half as many adherents as Hinduism, arose in the sixth century B.C. in India . It was a reaction to the less desirable features of Hinduism such as its strict social hierarchy that protected the privileged and kept millions mired in poverty.

Answer collision and mountain formation;

Your answer would be 625,000,000.