Answer:
8 if including the tube and 4 if just counting the roll of toilet paper itself.
Step-by-step explanation:
Well like the question says the diameter of the toilet paper is 12 cm full both including the toilet paper and the tube. But we are also told the tube has a Diameter of 4. Taking this into consideration we both know that the tube will never get smaller but we do know the roll will decrease in size by half so while keeping the diameter of the tube at 4 we evenly remove half of the other 2 and we are left with a diameter of 2 / 4 / 2 in which giving us a total diameter of 8 therefore the diameter now being 8. (pls let me know if im wrong though i doubt i am)