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

During an interview, the interviewer ordered hot coffee for the candidate to relieve the stress. The coffee was kept before him. After a minute, the interviewer asked him, 'What is before you?' He replied 'Tea'.

The candidate was selected immediately. Why?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

The sum of a mother, her baby and her dog's weight is 170 Kg. How much does the baby weigh if the mother weighs 100 kg more than the combined weight of the baby and the dog, and the dog weighs 60 per cent less than the baby?

Can you fill the blank with the correct number?

6 30 870 756030 _____

I am soft and cuddly that soothe your heart. But, If you pick my last name I am going to tear you all apart. Who am I?

What does this rebus puzzle means ?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

Our product and our sum always give the same answer. Who are we?