Math
posted by Marche on .
Suppose that 8 turns of a wire are wrapped around a pipe with a length of 60 inches and a circumference of 4 inches. What is the length of the wire

32 inches?
What am I missing?
What does the length of the pipe have to do with it? 
think you mean "...8 turns of wire are..."
I guess you mean that the wire starts at one end of the pipe and ends up at the other end of the pipe.
So the wire has travelled 60 inches along the length of the pipe and 32 inches around the pipe. If you imagine the sides of the pipe unwound to form a big rectangle, you could also imagine that the wire would be sort of travelling a diagonal of the rectangle, i.e. you can use Pythagoras:
x^2 = 60^2 + 32^2
x^2 = 3600 + 1024
x^2 = 4624
x = sqrt(4624) 
68