Logic Masters Deutschland e.V.

The solution is a word consisting of 4 different letters, first in puzzle a, then in b, then in c, then in d. You will find the solution with the process of elimination logic. Next to the words above, you find the following hints: white on black: the amount of letters which are in the solution and already on the right position. Black on white: the amount of additional letters which are also in the solution, but at a different position.

It's not hard, c'mon, give it a try :-)