A boatman on a bank of a river has to carry a dog, a cat and a container full of milk to the other bank in a boat, one at a time. The cat cannot be left alone with the milk or with the dog on either bank. What is the minimum number of times the boatman has to cross the river to carry all to the other bank?

Correct option is C

Given:
· Boatman can carry only one item at a time.
· The cat cannot be left alone with
· the milk, or
· the dog, on either bank.
Goal: Carry dog, cat, and milk safely to the other bank with minimum crossings.
Step-by-step solution
1. Boatman takes the cat to the other bank Left bank: Dog, Milk Right bank: Cat
2. Boatman returns alone Left bank: Dog, Milk Right bank: Cat
3. Boatman takes the dog to the other bank Left bank: Milk Right bank: Cat, Dog
(Cat cannot stay with dog, so something must be done.)
4. Boatman brings the cat back Left bank: Cat, Milk Right bank: Dog
5. Boatman takes the milk to the other bank Left bank: Cat Right bank: Dog, Milk
6. Boatman returns alone Left bank: Cat Right bank: Dog, Milk
7. Boatman takes the cat to the other bank Left bank: — Right bank: Dog, Cat, Milk
Total crossings
7 times
Correct answer:
(c) 7