Question

the inner circumference of a circular racing track is 440 the width of the track is 14 find the cost of fencing along the outer circle of the track at 100 per metre​

Answer 1

Answer:

Therefore, cost of bordering is Rs. 52,800.

Step by step explanation:

Given :

Inner circumference = 440 m

Width of the track = 14 m

Rate of fencing = Rs. 100 per m

To find :

The Cost of bordering the outer circle

Solution :

Consider the -

• Inner circle's radius as r
• Outer circle's radius as R

★ Radius of inner circle -

$\boxed{\rm{Circumference = 2 \pi r}}$

$\rm{\longrightarrow} \: 440 = 2 \times \dfrac{22}{7} \times r \\ \\ \rm{\longrightarrow} \: 440 = \dfrac{44r}{7} \\ \\ \rm{\longrightarrow} \: 44r = 440 \times 7 \\ \\ \rm{\longrightarrow} \: 44r = 3080 \\ \\ \rm{\longrightarrow} \: r = 70$

Radius = 70 m

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★ Radius of outer circle -

Radius of outer circle = Radius of inner circle + Width of the path

$\rm{\longrightarrow} \: 70 + 14 = 84$

Radius of the outer circle = 84 m

________________________________

★ Circumference of the outer circle -

$\boxed{\rm{Circumference = 2 \pi R}}$

$\rm{\longrightarrow} \: 2 \times \dfrac{22}{7} \times 84 \\ \\ \rm{\longrightarrow} \: \dfrac{3696}{7} \\ \\ \rm{\longrightarrow} \: 528$

Circumference = 528 m

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★ Cost of bordering -

$\rm{\longrightarrow} \: 528 \times 100 \\ \\ \rm{\longrightarrow} \: 52800$

Cost = Rs. 52800

Therefore, cost of bordering is Rs. 52,800.

Answer 2

Explanation:

Therefore, cost of bordering is Rs. 52,800.

Step by step explanation:

Given :

Inner circumference = 440 m

Width of the track = 14 m

Rate of fencing = Rs. 100 per m

To find :

The Cost of bordering the outer circle

Solution :

Consider the -

Inner circle's radius as r

Outer circle's radius as R

★ Radius of inner circle -

\boxed{\rm{Circumference = 2 \pi r}}

Circumference=2πr