answer these please
this is a case based maths question and is carrying 5m
Answers
Given:
- The length of each straight portion of the track is 90m
- Both the ends of the race track are semi circles
To Find:
- The answer of the following sub questions
Answers :
Given :
- Perimeter of the inner track is 400 m
To Find :
- The inner radius of the trak
Solution:
✦ Now, we know that the diagram is a fusion of a rectangle and 2 semi circles.
↷ According to the question
◕ The perimeter of the inner track is 400m
Now,
↦ Let's firstly find the lenght boundary of the inner perimeter excluding that of the circles
➼ 90m + 90m
➼ 180m
∴ The perimeter of two semicircles will be 400m - 180m
which is equal to 220m
We know,
↷ Perimeter of a semicircle = πr
So,
↷ Perimeter of 2 semicircles = 2πr
Now,
↦ Perimeter = 2πr
↦ 220m = 2 × 22 / 7 × r
↦ r = 220 × 7 / 22 × 2
↦ r = 1540/ 2 × 22
↦ r = 35m
- Henceforth the inner radius of the track is 35m
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Given:
- The outer radius of the track is 488m
To Find :
- The outer radius of the circle
Solution :
↷ According to the question :
✦ The perimeter of the outer track is 488m
Now,
↦ Let's firstly find the lenght boundary of the inner perimeter excluding that of the circles.
So,
- 90m + 90m = 180
∴ The perimeter of two semicircles will be 488m - 180m
which is equal to 308m
We know,
↷ Perimeter of a semicircle = πr
So,
↷ Perimeter of 2 semicircles = 2πr
Now,
↦ Perimeter = 2πR
↦ 308 = 2 × 22/7 × R
↦ R = 308 × 7 / 2 × 22
↦ R = 2156 / 44
↦ R = 49m
- Hence forth the outer radius of the track is 49m
Given :
- Outer radius = 49
- Inner radius = 35cm
To Find :
- The width of the track
Solution :
↷ Now,
- Let's find the width
◕ We know,
Width = Outer radius - Inner radius
↷ So,
Width = R - r
Width = 49 - 35
Width = 14m
- Henceforth the width of the track is 14m
We have,
- Width of the track = 14m
- Inner radius = 35m
- Outer radius = 49cm
To Find:
- The area of the track
Solution:
↷ Now, area is
↦ 2 [ 14 × 90 ] + [ {22 ÷ 7 × 49 × 49} - { 22 ÷ 7 × 35 ×35}]
↦ 2520m² + [ 7546m² - 3850m²]
↦ 2520m² + 3936m²
↦ 6216m²
- Henceforth the area of the track is 6216m²
We have,
- Area 6216m²
- Cost = 12.5 at m²
To Find,
- Total cost
Solution,
↷ Total cost
↦ Area × cost per m²
↦6216 × 12.50
↦77700
- Henceforth the cost of developing the track is 77700 Rupees
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We have,
Area 6216m²
Cost = 12.5 at m²
To Find,
Total cost
Solution,
↷ Total cost
↦ Area × cost per m²
↦6216 × 12.50
↦77700
Henceforth the cost of developing the track is 77700 Rupees
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