Answer: 
Step-by-step explanation:

Answer:
The answer is 20/3/4(without spaces) or 20 3/4.
Step-by-step explanation:
If three consecutive values add to 567 the middle value must be 567/3 = 189
Since the values are multiples of 9, the other values must be 189 - 9 and 189 + 9
The three values are 180, 189, 198