Question

C. the radius of circular field is 77m. It is surrounded by path of uniform width of 7m as shown in the
(3)
given figure. Find
i) The area of the path
ii) the cost of cementing the path at Rs 4/m2
77 m
Im​

Answer 1

Given :

• Radius of a circular field = 77 m
• The circular field is started by a path of uniform width = 7 m

To find :

• The area of the path
• Cost of cementing the path at the rate of Rs. 4/m²

Concept :

To calculate the area of the path :-

• Firstly, add 7 m to 77 m the resultant value will be the radius of the bigger circle. Calculate both the areas, then subtract the area of circular field from the area of the bigger circle. The value which we'll get will be the area of the path.

To find the cost of cementing :-

• Multiply the rate of cementing by the area of the path, the resultant value will be the cost of cementing the path.

Formula to calculate area of circle :-

• Area of circle = πr²

where,

• Take π = 22/7
• r denotes the radius of the circle

Solution :

Area of the circlular field :-

→ Area of the circlular field = πr²

→ Area of the circlular field = 22/7 × (77)²

→ Area of the circlular field = 22/7 × 77 × 77

→ Area of the circlular field = 22 × 11 × 77

→ Area of the circlular field = 18634

• Area of the circlular field = 18634 m²

Radius of the bigger circle :-

→ Radius of the bigger circle = 7 + 77

→ Radius of the bigger circle = 84

• Radius of the bigger circle = 84 m

→ Area of the bigger circle = πr²

→ Area of the bigger circle = 22/7 × (84)²

→ Area of the bigger circle = 22/7 × 84 × 84

→ Area of the bigger circle = 22 × 12 × 84

→ Area of the bigger circle = 22176

• Area of the bigger circle = 22176 m²

→ Area of the path = Area of the bigger circle - Area of the circular field

→ Area of the path = 22176 - 18634

→ Area of the path = 3542

Therefore,

• Area of the path = 3542 m²

Cost of cementing the path :-

→ Cost of cementing 1 m² of the path = Rs. 4

→ Cost of cementing 3542 m² of the path = 3542 × 4 = Rs. 14168

Therefore,

• Cost of cementing the path at the rate of Rs. 4/m² = Rs. 14168

Answer 2

Answer:

I hope it is very easy to understand as compared with other answers.