What does below science rebus mean?

Ag Ag Ag
Ag SPOON Ag
Ag Ag Ag

What has many teeth, but cannot bite?

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

Find three whole, positive numbers that have the same answer when multiplied together as when added together.

Can anyone tell me a word in the English dictionary which has a silent 'z'?

Three people enter a room and have a green or blue hat placed on their heads. They cannot see their own hat but can see the other hats.
The colour of each hat is purely random. They could all be green, blue, or any combination of green and blue.
They need to guess their own hat colour by writing it on a piece of paper, or they can write 'pass'.
They cannot communicate with each other in any way once the game starts. But they can have a strategy meeting before the game.
If at least one of them guesses correctly they win $10,000 each, but if anyone guesses incorrectly they all get nothing.
What is the best strategy?

I cannot talk, but I always reply when spoken to. What am I?

What came first, the chicken or the egg?

How many letters are in the alphabet?

There are two insects on a tile. Insect X is sitting on one side of the tile (point A) and Insect Y is sitting opposite on the other side of the tile (point B). Now both of them decide to change their position and thus X starts crawling to point B and Y starts crawling to point A. When they meet and pass each other in between, X takes 20 seconds to reach B and Y takes just 5 seconds to reach A.

Can you calculate the total time each of the insects took to change their positions?