Question

A racetrack is in the form of a ring whose inner circumference is 528 M and the outer circumference is 616 M .Find the width of the track.

Answer 1

let the radius of inner track = r

2 pie r = 352

r = 56

let the radius of outer track = R

2 pie R = 396

R = 63

width of track = radius of outer track - radius of inner track

=63 - 56

= 7 m.

Answer 2

A race track is in the form of a ring whose inner circumference is 396 m and the outer circumference is 418 m. Find the width of the track.

The outer circumference = 418 = (pi)(OD).

The inner circumference = 396 = (pi)(ID).

Hence (pi)(OD) -(pi)(ID) = 418 - 396 = 22, or

OD - ID = 22*7/22 = 7

The track width is thus 7/2 = 3.5 m.

Check: Radius of the outer track = 418/(2*pi) = 418*7/(2*22) = 66.5 m

Radius of the inner track = 396/(2*pi) = 396*7/(2*22) = 63 m

Track width = Radius of the outer track - radius of the inner track = 66.5 - 63 = 3.5 m.