We are the 3rd group of Greece 

Odysseus

Konstantinos

Sotiris

Hlias

First Challenge is addressed to Spanish group 5 

Challenge 1 από Odysseus Bozinakis

Second Challenge is addressed to Spanish group 1

Challenge 2 από Odysseus Bozinakis

Solution to the 1st challenge:

1st container     2nd container     3rd container

150ml                350ml                 0ml      

150ml                200ml                 150ml

300ml                200ml                 0ml

300ml                50ml                   150ml

450ml                50ml                   0ml

450ml                0ml                     50ml

100ml                350ml                 50ml

100ml                250ml                 150ml

250ml                250ml                 0ml 

 Solution to 2nd challenge:

Let the length of the tunnel be L and the speed of the cat be C, and the speed of the train be T.

Then, the distance the cat runs towards A is (3/8)L, and the distance the cat runs towards B is (5/8)L.

Let's consider the case where the cat runs towards A first.

The time it takes for the cat to meet the train at entrance A is given by:

(3/8)L / (T - C)

Similarly, the time it takes for the cat to meet the train at entrance B when it runs towards B is given by:

(5/8)L / (T + C)

Since the distances the cat runs towards A and B are equal, we can equate the two expressions and simplify:

(3/8)L / (T - C) = (5/8)L / (T + C)

Cross-multiplying and simplifying, we get:

3(T + C) = 5(T - C) 3T + 3C = 5T - 5C 8C = 2T T/C = 4

Therefore, the speed of the train is 4 times faster than the speed of the cat.