It takes ten identical pieces to form a circular track for a pair of toy racing cars. if the inside arc of each piece is 3.4 inches shorter than the outside arc, what is the width of the track?

 Length of outer track = sum of length of 10 pieces = circumference of the outer circle 

if R is the Radius of outer circle then... 

Circumference of the outer track = 2pi*R 

Similarly the circumference of the inner track (with radius r) = 2pi*r 

length of each outer piece is 3.4 inch more than length of inner piece 

So total outer length is 10*3.4 =34 inches more than the inner length. 

=> Outer Circumference - Inner Circumference = 34 inches 

=> 2pi*R - 2pi*r = 34 

=> 2pi(R -r) = 34 

=> R-r = 34/2pi = 5.41 inches 

=> R-r = Width of the track = 5.41 inches