Question

A woman is traveling with a​ wolf, a​ goose, and a mouse. She must cross a river in a boat that will only hold herself and one other animal. If left to​ themselves, the wolf will eat the goose and the goose will eat the mouse. How many crossings are required to get all four creatures across the river​ alive

Answer 1

W - wolf, G - goose, M - mouth

1. Woman takes G and crosses the river.

1st bank | 2nd bank

W, M      | G

2. She leaves G on the opposite  second bank and turns back.

1st bank | 2nd bank

W, M      | G

3. She takes W and goes with him to the bank where G already is.

1st bank | 2nd bank

M           | G, W and woman

4. She takes G back to the first bank and leaves W on the second bank.

1st bank | 2nd bank

G, M      | W

5. Woman leaves G on the first and takes M to the second bank.

1st bank | 2nd bank

G            | W, M

6. She leaves M on the second bank and returns to the first bank.

7. Takes G and delivers it to the second bank.

1st bank | 2nd bank

              | G, W, M and woman

Answer: 7 crossings.