Answer: The sequence rule is division. 80 divided by 2 = 40 divided by 2 = 20 divided by 2 = 10 and 10 / 2 equals 5.
Explanation:
The sequence is divided by 2 because when you divided 80 by 2, it equals the second pattern in the sequence, 40.
I worked it out by dividing every number by 2 and getting the same numbers in the pattern, I checked by doing the opposite, 40 x 2 = 80.
Hope this helps!