Answer: 1 unit
Explanation:
The diameters are 6 and 8, which cut in half to 3 and 4 respectively.
The difference in these radii values is 4-3 = 1.
This is the distance from one circle's edge to the other circle's edge, such that we're on the same line that goes through the center of the circles. This is the gap width or ring width so to speak.
