What is the below Rebus indicate?

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

You need to climb ten stairs. At every stair, you can either take one step up or you can jump two steps up.

In how many different ways you can climb 10 stairs?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

What has a bottom at the top?

If 2 workers can complete painting 2 walls in exactly 2 hours.

How many workers would be needed to paint 18 walls in 6 hours?

A farmer and his neighbour once went to Emperor Akbar"s court with a complaint. "Your Majesty, I bought a well from him," said the farmer pointing to his neighbour, "and now he wants me to pay for the water."
"That"s right, your Majesty," said the neighbour. "I sold him the well but not the water!"?
The Emperor asked Birbal to settle the dispute. How did Birbal solve the dispute?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

Identify The phrase in the picture.

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?