In the attached figure, you can see a chessboard and two rooks placed on the chess board. What you have to find is the number of squares that do not contain the rooks. How many are there?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

Before Mount Everest was discovered, what was the highest mountain in the world?

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

10 people came into a hotel with 9 rooms and each guest wanted his own room. The bellboy solved this problem.
He asked the tenth guest to wait for a little with the first guest in room number 1. So in the first room, there were two people. The bellboy took the third guest to room number 2, the fourth to number 3, ..., and the ninth guest to room number 8. Then he returned to room number 1 and took the tenth guest to room number 9, still vacant.
How can everybody have his own room?

Find the number of squares in the below-given picture.

Can you complete the sequence?

192, 021, 222, 324, 252, 627, 2__, 9__?