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
