Answers ASAP PLEASE!

Question

A running track is the ring formed by two concentric circles. If the circumferences of the two circles differ by  feet, how wide is the track in feet?

Answer 1

C_outer - C_inner = 10π

C_{outer =} 2πr_outer

C_inner = 2πr_inner

2πr_outer - 2π_inner = 10π

r_outer - r_inner = 5

Answer 2

Let C₁ = circumference of inside circle, & r₁ = radius of the inside circle

C₂ = circumference of outside circle, & r₂ = radius of the outside circle

Then,

C₂ - C₁ = 10*pi or 2*pi*r₂ - 2*pi*r₁ = 10*pi or r₂ - r₁ = 5

So the track is 5 feet wide.