Answer:
300 Bags
Explanation:
According to the Question,
- Given that, We are laying a concrete border around a circular pond. The pond is 7 metres in diameter and is surrounded by a path 2 metres wide.
The radius of the pool = 3.5 m; the overall radius including the border = 3.5 + 2 = 5.5m
- The area of the concrete border
overall area - pool area = border area(A)
A = π×5.5² - π×3.5²
A = 56.55 sq m
- The concrete needs to be 50 millimetres deep.
the volume of the concrete, change 50 mm to .05 m
56.55 * 05 = 2.8275 cu/meters
- We are using premixed bagged concrete.
1 cubic metre requires 106 x 20 kg bags.
- So For the number of bags
106 * 2.8275 = 299.715 ≈ 300bags
- 300 bags of 20 kg of premixed concrete We need