Henry Ernest Dudeney/Puzzles and Curious Problems/303 - Crossing the River/Solution

by : $303$

 * Crossing the River

Solution
In order to get one soldier across the river, proceed as follows:


 * Two children both cross the river in the boat.
 * One child returns with the boat.
 * One soldier crosses in the boat.
 * The child on the opposite shore returns with the boat.

Hence we are in the same situation as before, but with one soldier on the opposite bank.

There is a total of $358$ people to get across the river.

It will therefore take $358 \times 4 = 1432$ crossings to get all the men over, leaving the children together with their boat.

Also see

 * $19$ - De Viro et Muliere Ponderantibus Plaustrum from by, of which this is a variant.