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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 R_{1} and outer radius be R_{2}

Inner circumference = 2πR_{1} = 352 m

⇒ 2 × 22/7 × R_{1} = 352 m

⇒ R_{1} = 352 × 1/2 × 7/22

⇒ R_{1} = 56 m

Outer Circumference = 2πR_{2} = 396 m

⇒ 2 × 22/7 × R_{2} = 396 m

⇒ R_{2} = 396 × 1/2 × 7/22 m

⇒ R_{2} = 63 m

Width of the track = R_{2} – R_{1} = 63 m – 56 m = 7 m

Area of track = = 22/7 × (63^{2} -56^{2})

= 22/7 × (3969 – 3136) m^{2}

= 22/7 × 833 m^{2} = 2618 m^{2}

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