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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?
Answers
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