Originally Posted by monaro

A River Crossing.

There are two boys each weighing 40kgs who deside to earn some pocket money in
the holidays. They deside to use their small row boat with a maximum capacity of
80kgs total, to enable the two of them to earn their pocket money.

They deside to wait beside a river bank after a storm a week before destroyed the
only bridge for miles that was used as a normal means of crossing such a wide river.

The one day in question a group of 11 adults each weighing 80kgs who are passing
through needed to cross this river at this very same point. They are all on the same
side as the two boys of the river.

They deside to pay to get over to the other side as there is no other way to get
accross this river with understanding that they are not going into the river except
crossing by this small row boat.

The fee is charged at one dollar for each pass that the row boat makes to cross the
river. At the end of the day both boys must be on the same side as they all started.

Q. How much money did the two boys make that day in question?

A. ?