The term "cranium" describes your skull.
25 is the answer
23+25+27+29+31
What's the models and the situations? Not sure if there's a pic but it's not visible.
This would be
1 + 2^1 + 2^3 = 11 in decimal
One complete rotation, uses up the whole circumference, and the longer the diameter, the longer the circumference.
for a bike wheel, the longer the circumference or its perimeter, the more it goes, since the tire is longer. A 27in tire will cover more ground in one-go-around than a 25in tire.
let's just check how much ground each one cover, and get their difference.