Question

For
6. A ground is in the form of a circle whose diameter is 350 m. An at sen
revolutions. Find the distance covered by the athlete.
7 A wire of length 1320 cm is made into circular frames of radius 7 cm each
frames can be made?
A Rose garden is in the form of circle of radius 63 m. The gardener wants
the rate of 150 per metre. Find the cost of fencing?​

Answer 1

Answer:

Ques 6: A ground is in the form of a circle whose diameter is 350 m. An at sen  revolutions. Find the distance covered by the athlete.

ans:  

The diameter of the circle, d = 350 m

Revolutions made by the athlete = 10

In 1 revolution, the athlete covers a distance equal to the circumference of the circle, therefore,

Circumference = 2πr = 2 * 22/7 * 350/2 = 1100 m

Thus,

The distance covered by the athlete in 10 revolutions,

= 10 * 1100

= 11000 m

= 11 km.

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Ques 7: A wire of length 1320 cm is made into circular frames of radius 7 cm each  frames can be made?

ans:

Total length of the wire = 1320 cm

Certain no .of circular frames each of radius 7 cm are made from 1320 cm wire.

So,the circumference of each circular frame = 2 * 22/7 * 7 = 44 cm

Thus,

No. of circular frames that can be made  

= [Total length of the wire] / [circumference of each circular frame]

= 1320 / 44

= 30

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Ques 8: A Rose garden is in the form of circle of radius 63 m. The gardener wants  the rate of 150 per metre. Find the cost of fencing?

Ans:  

The radius of the garden = 63 m

Rate of fencing = Rs. 150 per meter

Since we are doing the fencing of the garden, therefore, we need to find the circumference of the circle i.e.,  

Circumference = 2 * 22/7 * 63 = 396 m

Thus,  

The cost of fencing the garden is,

= Rs. 150 * 396 m

= Rs. 59400