10
20
20
1/2 or 10 are not yellow, so they are either red or green. Since 4 are red, the remaining 6 are green.
Probability of NOT green = 1 - 6/20 = ?
First, let's find the total number of colored tiles in the bag. We know that 1/2 of the tiles are not yellow. Since yellow is one of the three colors, it means the remaining 1/2 of the tiles are divided among red and green. So, the total number of colored tiles is 1/2 of the total number of tiles, which is (1/2) * 20 = 10 tiles.
Next, let's find the total number of non-green tiles. We know that 1/5 of the tiles are red, so the number of red tiles is 1/5 of the total number of tiles, which is (1/5) * 20 = 4 tiles. Since we have 20 total tiles and 4 of them are red, it means the remaining non-green tiles are 20 - 4 = 16 tiles.
Now that we have the total number of non-green tiles (16) and the total number of colored tiles (10), we can calculate the probability. The probability of randomly selecting a non-green tile is given by:
P(non-green) = (number of non-green tiles) / (total number of colored tiles)
P(non-green) = 16 / 10
P(non-green) = 8 / 5
So, the probability of randomly selecting a colored tile from the bag that is not green is 8/5 or 1.6.