Question

To landscape his 70 ft by 60 ft backyard, Austin is planning first to put down a 4 inch layer of topsoil. He can buy bags of topsoil at $2.50 per 3-ft3 bag, with free delivery. Or he

can buy bulk topsoil for $22.00/yd, plus a $20 delivery fee. Which option is less expensive?
I need volume of soil, cost of bags and cost of bulk

Answer 1

Bulk is less expensive

Explanation:

First convert inches to feet: 4 in x 1 ft/12 in =0.333 ft

Volume of topsoil needed = 70 x 60 x 0.333 = 1400 ft³

Bagged topsoil: 1400 ft³ x $2.50/3 ft³ = $1166.67

Bulk: 1400 ft³ x 1 yd³/27 ft³ x $22.00/yd³ + $20 = $1160.74

Bulk is just a little cheaper

Answer 2

To calculate the volume of soil needed, we first convert the dimensions of the backyard to feet:

Length = 70 ft

Width = 60 ft

Depth = 4 in = 4/12 ft = 1/3 ft

Volume = Length x Width x Depth

Volume = 70 ft x 60 ft x (1/3) ft

Volume = 1400 ft³

Option 1: Bags of topsoil

Each bag of topsoil contains 3 ft³ of soil, so the number of bags needed is:

Number of bags = Volume / Bag size

Number of bags = 1400 ft³ / 3 ft³ per bag

Number of bags = 467 bags

The total cost of bags of topsoil is:

Cost = Number of bags x Cost per bag

Cost = 467 bags x $2.50 per bag

Cost = $1167.50

Option 2: Bulk topsoil

The volume of topsoil needed is 1400 ft³, which is equivalent to:

Volume = 1400 ft³ / 27 ft³ per yd³

Volume = 51.85 yd³ (rounded to two decimal places)

The cost of bulk topsoil is:

Cost = Volume x Cost per yd³ + Delivery fee

Cost = 51.85 yd³ x $22.00 per yd³ + $20.00 delivery fee

Cost = $1153.70

Therefore, buying bulk topsoil is less expensive than buying bags of topsoil. The cost of bulk topsoil is $1153.70, while the cost of bags of topsoil is $1167.50