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

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

I travel all around the world but always stay in the corner. What am I?

John bought 150 chocolates but he misplaced some of them. His Father asked him how many chocolates were misplaced.
He gave the following answer to him:
If you count in pairs, one remains
If you count in threes, two remain
If you count in fours, three remain
If you count in fives, four remain
If you count in sixes, five remain
If you count in sevens, no chocolate remains.

Can you analyze the statements and tell us how many chocolates were lost?

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

In the figure, you can see nine stars. What you have to do is connect all of them by using just four line and without lifting your hand i.e. in a continuous flow.

Can you guess the name of the month by looking the below rebus ?

What are the 50th, 63rd and 100th numbers in the sequence below?
4, 5, 8, 8, 9, 9, 12, 13, 13, 13, 17, 18, ...

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?

What's the only room from which no one can enter or leave