Answer:
4.63 cubic yard.
Explanation:
Given,
The length of sidewalk, l = 100 feet,
Width, w = 5 feet,
Depth, h = 3 inches = 0.25 feet,
Thus, the volume of the concrete needed for making the sidewalk,
![V=l* w* h](https://img.qammunity.org/2020/formulas/mathematics/middle-school/xnsv4vbuc0hwx2rzbptiuzjmngsqr6m1kp.png)
![=100* 5* 0.25](https://img.qammunity.org/2020/formulas/mathematics/college/qwpvrijnkwphts708h4ft8f6p4ynmtxbvi.png)
= 125 cubic feet,
∵ 1 cubic yard = 27 cubic feet,
⇒ 1 cubic feet =
cubic yard,
Thus, the quantity of concrete needed =
≈ 4.63 cubic yard.