what does the below rebus means?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

Before Balboa discovered the Pacific Ocean, which was the largest ocean before that?

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?

Can you count the number of triangles in the given figure?

A woman lives in a skyscraper thirty-six floors high and is served by several elevators which stop at each floor going up and down. Each morning she leaves her apartment and goes to one of the elevators. Whichever one she takes is three times more likely to be going up than down. Why?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

Find the number of squares in the below picture

John went to a parrot shop in Mexico, and the parrot owner told him that his parrot is so unique that he repeats everything he hears. John got excited and immediately bought the parrot. John went home and spoke many words, but the parrot does not repeat anything.
He went again to the parrot shop and complaint to the shopkeeper, but the shopkeeper never lied. Explain?

You are given four tennis balls and asked to arrange those balls in a manner that the distance between each one of them is exactly equal. How will you do it?