Can you decipher the below rebus?

PBLUESAISNUERSES

What happened when the wheel was invented?

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?

I look flat, but I am deep. Hidden realms I shelter. Lives I take, but the food I offer. At times I am beautiful. I can be calm, angry, and turbulent. I have no heart but offer pleasure as well as death. No man can own me, yet I encompass what all men must have. What am I?

On her drawing table, Sayna lit 12 coloured candles. A few seconds later she blew two candles off.

How many candles Sayna have at the end?

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?

What number should come in place of the question mark below?

What number comes next in this sequence:
7 8 5 5 3 4 4 _

Count the squares in the matchstick puzzle below?

How many triangles can you count in the figure given?