a grand father who had 3 daughters had commited a deal with thier 3 daughters that they should double what ever the amount he had that time at his pocket. " actually the homes of all the sisters will be in a row such dat there will be an entrance gate with watch man and an exit gate with a watch man ..
all the three homes have the same type . but there is a tradition of bribing the watch man , means the person should give exactly 1 penny (1 rupee) when ever he passed by any gate irrespective of entrance or exit.. the procedure of bribing at the watchmans and the doubling of the money is consecutively done successfull at all the three daughters houses ..
"how much money should the grand father should take initially such that the money when he passed by the 2nd watch man at the third watch man .. will be a ZERO .. ??"