What is the below Rebus indicate?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

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

A man has to get a fox, a chicken, and a sack of corn across a river.

He has a rowboat, and it can only carry him and one other thing.
If the fox and the chicken are left together, the fox will eat the chicken.
If the chicken and the corn are left together, the chicken will eat the corn.

How does the man do it?

Different lights make me strange by changing me into different sizes. What am I?

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

Why is a river so rich ?

Why is it very easy to weigh a fish?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?