If the area of the room is 15 square meters, how many square meters are the floor areas of the two kinds of floor tiles
Black brick: white brick = 1:2
1+2=3
So black brick is 1 / 3
White brick is 2 / 3
So black brick = 15 times 1 / 3 = 5 square meters
White brick = 15 times 2 / 3 = 10 square meters
(or white brick = 15-5 = 10 square meters)