A farmer wants to exchange his cows for chickens. One of his neighbours will give him 3 sheep for 2 cows, another will give him 4 goats per each sheep, and the third will give him 2 chickens per 3 goats. How many
chickens can he get if he has 300 cows?

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.