The circumference is 3 inches and the length of tube is 16 inches. The string is wrapped around symmetrically around the tube. What is the length of the string?

Answer 1

If the string covers the entire surface area, consider it a bunch of 3-inch circles.

Now, you have to know the diameter of the string. If it is 1/20 inch, then there will be 16*20 = 320 loops.

So, nail that down, and you can answer the question.