Can you replace the question mark with the correct number?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

A time long back, there lived a king who ruled the great kingdom of Trojan House. As a part of the renovation of the kingdom to meet future security needs, he asked his chief architect to lay down a new play in a manner that all of his 10 castles are connected through five straight walls and each wall must connect four castles together. He also asked the architect that at least one of his castles should be protected with walls. The architect could not come up with any solution that served all of King's choices, but he suggested the best plan that you can see in the picture below. Can you find a better solution to serve the king's demand?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

Can you tell a 3D object that has just two surfaces?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

Replace the question mark with the correct number below.

Replace the question mark with the correct number.

2 + 2= 4
3 + 3= 18
4 + 4= 48
5 + 5= ?

John has eleven friends. He has a bowl containing eleven apples. Now He wants to divide the eleven apples among his friends, in such a way that an apple should remain in his bowl.
How can He do it?

Can you find the odd number in the following?

2716, 4135, 5321 and 7145