The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

A tourist visits a small town for his research. While in the town, he decides to get a haircut. Since the town is quite small, there are only two barbers in the town � one on the North Street and one on the South Street. The barbershop on the North Street is a mess and the barber has a weird and pathetic haircut. While the barbershop at the South Street is pretty tidy and the barber as well has an impressive haircut.

Which barbershop will the tourist visit for his haircut and why?

Can you move 2 matchsticks to form four equal sized squares.

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

John can place six large boxes or nine small boxes into a carton.

Can you find out in how many cartons can he place sixty-six boxes in total?

By using 'because' continuously three times, can you make an English statement ?

I have holes on the top and bottom. I have holes on my left and on my right. And I have holes in the middle, yet I still hold water. What am I?

What jumps when it walks and sits when it stands?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?