People put me on the table and cut me but do not eat me. What am I?

You can see three almost identical images below. Can you spot the odd one out from them?

You are mixing a mixture of cement and Sand with five gallons of water. You have a garden hose giving you all the water you need. The problem is that you only have a four-gallon bucket and a seven-gallon bucket and neither has graduation marks. Find a method to measure five gallons.

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

You walk into a room where there are three primates held in their respective cages:
1) A lion who is eating the flesh of a goat.
2) An orangutan who is playing with blocks.
3) A donkey who is sitting idle.

Who is the most intelligent primate in the room?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

Can you move 2 matchsticks to form four equal sized squares.

In a jungle where there are no street lights or any other artificial source of lights, I notice a black snake crossing the road.
How did I get sight of the snake?

What happened when the wheel was invented?

Can you spot the hidden girl in the picture below?