Dirt cut 2 ft deep from a section of land 35 ft by 67 ft is used to fill a section 26 ft by 26 ft to a depth of 4 ft. How many cubic yards of dirt are left after the fill?

(Type an integer or decimal rounded to the nearest tenth as needed.)



Answer :

Certainly! Let's break down the problem step-by-step:

1. Calculate the volume of dirt removed:
- Start by determining the dimensions of the section from which the dirt is removed: Length = 35 feet, Width = 67 feet, and Depth = 2 feet.
- Convert the depth from feet to yards. Since 1 yard = 3 feet:
[tex]\[ \text{Depth in yards} = \frac{2}{3} \text{ yards} \][/tex]
- The volume of dirt removed is given by:
[tex]\[ \text{Volume (cubic yards)} = \frac{\text{Length (ft)} \times \text{Width (ft)} \times \text{Depth (yards)}}{27} \][/tex]
Using the dimensions provided:
[tex]\[ \text{Volume cut} = \frac{35 \times 67 \times \left(\frac{2}{3}\right)}{27} \][/tex]
Simplifying inside the parentheses first:
[tex]\[ 35 \times 67 = 2345 \][/tex]
[tex]\[ 2345 \times \frac{2}{3} = 1563.33 \][/tex]
[tex]\[ \text{Volume cut} = \frac{1563.33}{27} \approx 57.9 \text{ cubic yards} \][/tex]

2. Calculate the volume required to fill the new section:
- The dimensions of the fill section are: Length = 26 feet, Width = 26 feet, Depth = 4 feet.
- Convert the depth from feet to yards:
[tex]\[ \text{Depth in yards} = \frac{4}{3} \text{ yards} \][/tex]
- The volume of dirt needed to fill the new section is given by:
[tex]\[ \text{Volume (cubic yards)} = \frac{\text{Length (ft)} \times \text{Width (ft)} \times \text{Depth (yards)}}{27} \][/tex]
[tex]\[ \text{Volume fill} = \frac{26 \times 26 \times \left(\frac{4}{3}\right)}{27} \][/tex]
[tex]\[ 26 \times 26 = 676 \][/tex]
[tex]\[ 676 \times \frac{4}{3} \approx 902.67 \][/tex]
[tex]\[ \text{Volume fill} = \frac{902.67}{27} \approx 33.4 \text{ cubic yards} \][/tex]

3. Calculate the remaining volume of dirt:
- Subtract the volume needed to fill the new section from the volume of dirt removed:
[tex]\[ \text{Volume left} = \text{Volume cut} - \text{Volume fill} \][/tex]
[tex]\[ \text{Volume left} = 57.9 - 33.4 \approx 24.5 \text{ cubic yards} \][/tex]

In conclusion, the volume of dirt left after filling the new section is approximately 24.5 cubic yards, rounded to the nearest tenth.