Numerals for the Given Number Names up to Billions

Q.

How many thousand make a crore?

Q.

Solve the riddle:
(I) I am a number in Billions, but less than 10 Billion.

(II) I'm formed using the digits 0 and 5.
I am

1. $50,000,000,000$
2. $50,000,000$
3. $5,000,000$
4. $5,000,000,000$