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

If it took eight men ten hours to build a wall, how long would it take four men to build it?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

On a windy rainy night , I was driving in my car.
When i reach the bus stand , i see three people waiting for the bus.

1. An old lady who needs an immediate medical attention
2. My Best Friend
3. Girl whom i love from childhood

My car is a two seat, so can you tell me , what i have done in this situation ?

We can be boring,Or interesting.
We can be long,Or short.
We can have pictures,Or just words.
Many love us,But many also hate us.
What are we?

While handling a project, the landscaper is asked by the owner of the mansion that he wants four trees in front of his mansion that are exactly equidistant from each other.

How will he do it?

There is a five-letter word which has 3 consonants(all are same) and 2 different vowels.
Also, something wrong is associated with the word.

Can you name it?

Find the next number in the sequence

5 12 24 36 ?

Can you start the fire using two pieces of wood?

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?