From the information given, the number of outcomes from 20 trials are
Red = 7
Yellow = 6
Blue = 7
From the outcomes, since the number of outcomes for red and blue are equal, it means that the number of red and blue faces would be the same. The only option where they are the same is the last option. Since the total number of faces is 6, the remaining face which is yellow is possibly 2. Thus, the correct option is
The cube has 2 red faces, 2 blue faces and 2 yellow faces