A ball is placed at the top left corner of a maze. It falls down the maze from platform to platform until it reaches one of the slots at the bottom. The ball always moves in the same way. It starts by going to the right. Every time it falls from one platform to another, it changes direction. You can see an example on the left.

Which slot will the ball reach in the maze on the right?

A Beaver has developed special instructions for paper folding. These instructions can be used to explain how to fold a piece of paper with straight sides. One of the commands in this instruction is fold.

e = fold(a, b) means:
fold the piece of paper in a way that side ‘a’ is lying completely on side ‘b’. That way, you create a new side, the fold. This line is called ‘e’.

Please note that the paper remains on the table during folding, and that the length of side b is twice the length of side a.
How does the paper rectangle (a, b, c, d) look like after the execution of these three instructions?
e = fold(c, a); f = fold(c, d); g = fold(a, f)

A)

B)

C)

D)

There are two kinds of tunnels in Bebras Land. When beavers enter a black tunnel one after the other, they come out in reversed order. When beavers enter a white tunnel one after the other, when they come out, only the first and the last beavers are interchanged.

A beaver family goes through thess three tunnels:

In what order are they arranged when they come out of the last tunnel?

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