Can you place three balls such that the equation shown in the picture holds true?

Birbal was jester, counsellor, and fool to the great Moghul emperor, Akbar.
The villagers loved to talk of Birbal's wisdom and cleverness,
and the emperor loved to try to outsmart him.
One day Akbar (emperor) drew a line across the floor.
"Birbal," he ordered, "you must make this line shorter, but you cannot erase any bit of it."
Everyone present thought the emperor had finally outsmarted Birbal.
It was clearly an impossible task.
Yet within moments the emperor and everyone else present had to agree that Birbal had made the line shorter without erasing any of it.
How could this be?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

I’m light as a feather, yet the strongest person can’t hold me for five minutes. What am I?

What goes up but never comes down?

On my way to St. Ives I saw a man with 7 wives. Each wife had 7 sacks. Each sack had 7 cats. Each cat had 7 kittens. Kittens, cats, sacks, wives. How many were going to St. Ives?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

If your uncle’s sister is not your aunt, what relation is she to you?

If "P" means "-", "Q" means "/", "R" means "+", and "S" means "*" then find the value of the following:

21 Q 7 R 9 S 10 P 13

I have feet, but no legs. Which animal Am I?