Initial Amount in Wallet?
On the festival of Raksha Bandhan (holy festival where brother-sister relationship celebrated), Mayank decides to visit his 3 sisters. He takes certain amount with in his wallet & goes to first sister. While without his notice first sister puts equal amount of money as in wallet. After tying rakhi, Mayank gifts her Rs.2000. Now he moves to second sister. While Mayank takes a breakfast, the second sister secretely doubles the money that was in Mayank's wallet. Again after tying rakhi, Mayank gifts her Rs.2000. At third sister's home, while he enjoys delicious lunch cooked by his sister, third sister doubles money in his pocket. Once again after tying rakhi, Mayank gifts third sister Rs.2000.Now there were Rs.5000 in his wallet.