An old man was traveling to his sister's home with a Tiger a goat and a bundle of green grass. while traveling he arrives at a river bank where he finds a very old boat that can carry the weight of maximum man and one other thing (goat,lion or grass). But if he takes the lion on the boat, the goat will eat grass. Similarly, if he carries grass with him then lion will kill the goat.
How can the man carry all three to the other end of the river?