Can you place six X (crosses) in below board without making three in a row in any way ?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

Chhote se Chintu Miyan,
Lambi si Pooch.
Jahan Jaye Chintu Miyan,
Wahan Jaye Pooch.

छोटे से चींटू मियाँ,
लंबी सी पूंछ।
जहाँ जाये चींटू मियाँ,
वहाँ जाये पूंछ।

Bolo kya?

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

If you’ve got me, you want to share me; if you share me, you haven’t kept me. What am I?

Thirty friends were on a hiking trip when they decided to enjoy the bonfire. They assembled for it and agreed to play a game. For that, they divided themselves into five teams with seven members each, forming five rows.

How did they manage to achieve this formation?

A family is trapped in a jungle. There is a bridge which can lead them to safety. But at one time, the bridge can only allow two people to pass through. Also, all of them are afraid of the dark and thus, they can't go alone.

Father takes 1 minute to cross, the mother takes 2 minutes, the son takes 4 and the daughter takes 5 minutes. While crossing the time taken will be according to the slower one. How can they all reach the other side in the minimum possible time?

Solve the following series:
AZ, GT, MN, __, YB

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?