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

Puzzles and Curious Problems by Henry Ernest Dudeney: $303$

During the Turkish stampede in Thrace, a small detachment found itself confronted by a wide and deep river.

However, they discovered a boat in which two children were rowing about.

It was so small that it would only carry the two children, or one grown up person.

How did the officer get himself and his $357$ soldiers across the river and leave the two children finally in joint possession of their boat?

And how many times need the boat pass from shore to shore?

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.