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

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

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

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

Only one color, but not one size,
Stuck at the bottom, yet easily flies.
Present in sun, but not in rain,
Doing no harm, and feeling no pain.
What is it?

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

There are two dice with empty faces in front of you and a marker. You can mark any number on each of the faces of the two dice, but you have to display all 31 days of the month using the two of them.

Which numbers will you mark on which dice so that you can easily depict all the dates of the month?

Can you spot the man between the coffee bean in the picture below ?

The centre of the third figure is empty. What digit should fit inside?