John, Leslie, Michael, and Patrick weigh 56Kg, 59Kg, 62Kg and 120Kg respectively. They want to cross a river using a boat with a capacity of 120Kg. Find a way to get all of them across the river with the minimum number of rows. You must show your rows using the most suitable notations from the lecture notes (Unit 2).

Answer: you have to find the required rows by trial and error and show the answer as follows: The following shows the minimum number of rows that get across: {JLMP||} {MP|JL, |} {MP||JL} ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,