It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

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

Give it food and it will live; give it water and it will die.

If all Goats are Sheep and all Sheep are Deers, are all Deers Goats ?

Create a number using only the digits 4,4,3,3,2,2,1 and 1. So i can only be eight digits. You have to make sure the ones are separated by one digit, the twos are separated by two digits the threes are separated with three digits and the fours are separated by four digits

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

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.

You need to complete the maze by entering from the entrance marked below in the figure near the yellow circle, bottom left and leaving from the exit point near the green circle, bottom middle.

Rule of Game: You can move only by exchanging green and yellow circles.

Can you find the thief by just looking at the picture below?

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?