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

Spot what is wrong here in below Picture?

Do you know of a place where the wind blows south and then suddenly shifts direction towards the north?

Why is the Hole below a Lock?

Using Only Five 5's and any mathematical operator make sum as 37

What breaks yet never falls, and what falls yet never breaks?

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

You have to fill the below given grid in a manner that every row and column contains the digits 1 to 6. Also, make sure that the squares that are connected with each other must contains the same digit.

There is a box. The area of its top is 240 square units, the area of the front is 300 square units and the area of the end is 180 square units.

Can you calculate the dimensions of this box with the given data?

You board a train. The train will have to enter a tunnel soon. You are claustrophobic. Which place is the best for you to sit?