A racetrack is in the form of a ring whose inner circumference is 352 m and outer circumference is 396 m. Find the width and the area of the track.

Let the inner radius be R1 and outer radius be R2


Inner circumference = 2πR1 = 352 m


⇒ 2 × 22/7 × R1 = 352 m


⇒ R1 = 352 × 1/2 × 7/22


⇒ R1 = 56 m


Outer Circumference = 2πR2 = 396 m


⇒ 2 × 22/7 × R2 = 396 m


⇒ R2 = 396 × 1/2 × 7/22 m


⇒ R2 = 63 m


Width of the track = R2 – R1 = 63 m – 56 m = 7 m


Area of track = = 22/7 × (632 -562)


= 22/7 × (3969 – 3136) m2


= 22/7 × 833 m2 = 2618 m2


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