Question

a cyclist travels around a circular track of diameter 200 m. The distance travelled by cyclist after covering three and half round of the circular track is:-
(i) 1.1 km
(ii) 1.8 km
(iii) 2.2 km
(iv) 0.2 km ​

Answer 1

Answer:

• (iii) 2.2km

Explanation:

Given, diameter of the track is 200 metres

Since, diameter is 2× radius

∴ Radius of the track will be 200/2 = 100 metres.

Now,

The cyclist covers 3½ round of the track.

Calculating it's perimeter,

Perimeter of the track is given by,

→ 2πr

Where,

• r denotes the radius = 100m
• Taking π as 3.14

→ 2 × 3.14 × 100

→ 628 metres

Then,

The cyclist covers 3½ of 628 metres

Or,

→ 7/2 of 628

→ 7/2 × 628

→ 7 × 314

→ 2198 metres

Converting into km

Since, 1km = 1000 metres

→ 2198 ÷ 1000

→ 2.198

→ 2.2km (approx.)

Hence, the cyclist travels 2.2km approx.

_____________________

Formula used:

→ Perimeter of a circle = 2πr

Where, ‘r’ denotes the radius of the circle.

Conversion:

• 1km = 1000m

Answer 2

Step-by-step explanation:

(iii) 2.2km

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