Can you find the odd number in the following?

2716, 4135, 5321 and 7145

I am beautiful, up in the sky. I am magical, yet I cannot fly. To people I bring luck, and to some people, riches. The boy at my end does whatever he wishes. What am I?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?

Which alphabet is a part of our body?

A boy collects white seashells from the sea and brings them home every night. When he has enough of them, he decides to sell them to a trader.

The trader is ready to buy the shells and he asks the boy about the quantity. At this, the boy starts calculating. He has a giant box that contains 3 mini boxes. Two of them have another mini box inside. If the giant box can hold 50 shells, how many brown shells can he sell to the trader?

John went to a parrot shop in Mexico, and the parrot owner told him that his parrot is so unique that he repeats everything he hears. John got excited and immediately bought the parrot. John went home and spoke many words, but the parrot does not repeat anything.
He went again to the parrot shop and complaint to the shopkeeper, but the shopkeeper never lied. Explain?

What Does this text mean:

important=important

You have a square. What you have to do is cut and reassemble the square such that you create a Red Cross sign that has the same volume as that of the square.

I make two people out of one. What am I?