IPL Auction

Suppose in IPL auction KKR start their bidding with ₹x billion. They invest half of the total money plus ₹$\frac{1}{2}$ billion on first player. On the second player, They invest half of the rest plus ₹$\frac{1}{2}$ billion, and so on. On the eleventh (i.e. last) player they invest half of what remains plus ₹$\frac{1}{2}$ billion. And finish all their money. Find the value of x (in billion).