Why do we preferably have round manhole covers and not square ones?

A word I know has six letters it contains, remove one letter and 12 remain. What is it?

The Little ant seems to be always confused. Do you know why?

If Rajina's daughter is my daughter's mom, who am I to Rajina?

You need to arrange three 7 and mathematical symbols to form number 1?

What is the next number in this series?

4,12,84,3612....

All of Jacob's shoes are red except two.
All of Jacob's shoes are green except two.
All of Jacob's shoes are yellow except two.

How many shoes does Jacob have?

I look at you, you look at me I raise my right, you raise your left. What am I?

For an extra income, John decided to work at a Hotel for one hour daily. The manager offers him that they will pay him $11 after every 11 days.
However, John offered a different proposition to the manager. The offers stand as:
He will be paid just a penny on his first day.
Two pence will be paid on the second day,
Four pence will be paid on the third day.
And so on till the 11th day.

Should the Hotel manager accept his offer?

It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?