If there are 20 red marbles, then there are 3 * 20 = 60 green marbles.
Yellow marbles make up 20% of the green marbles, so there are 0.20 * 60 = 12 yellow marbles.
The total number of red, green, and yellow marbles is 20 + 60 + 12 = 92 marbles.
The total number of all marbles in the box is three times more than the number of green marbles, so there are 3 * 60 = 180 marbles in total.
Therefore, the number of marbles of a different color is 180 - 92 = 88.
#### 88
The answer is: 88
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
In a big box, there are marbles in 4 colors. Inside, there are 20 red marbles.  There are three times more green marbles than red.  Yellow marbles make up 20% of the green marbles. How many marbles are of a different color if the total of all marbles in the box is three times more than the number of green marbles?

### Answer:
