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

Can you find the least possible number such that

If the number is divided by 3, it gives the remainder of 1;
If the number is divided by 4, it gives the remainder of 2;
If the number is divided by 5, it gives the remainder of 3;
If the number is divided by 6, it gives the remainder of 4.

In a stable, there are men and horses. In all, there are 22 heads and 72 feet. How many men and how many horses are in the stable

Can you find out which number multiplied by itself will give the output as 12345678987654321?

Get total of 120 by using five zeros 0,0,0,0,0 and any one mathematical operator.
Do you ?

I want to fill my bucket using both cold and hot water.
I have two taps for both cold and hot water. The hot water tap fills the bucket in exact 6 hours and the cold water tap fills the bucket in exact 4 hours.
I turn both of them simultaneously but I forgot to turn off another tap which removes the water out of the bucket. This tap can empty the bucket in 12 hours.

How Long will it take to fill the bucket?

The product of three consecutive numbers is 7980.
Then the sum of these consecutive numbers would be?

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

which number am I?

Solve the mathematical equation in the picture below.

A chicken farmer has figured out that a hen and a half can lay an egg and a half in a day and a half. How many hens does the farmer need to produce one dozen eggs in six days?