   SEARCH HOME Math Central Quandaries & Queries  Question from dianna, a parent: This is a 2-fold question. I am getting some mulch that is measured in 1 cubic yard for $25.00. Walmart has a 2 cubic bag for$3.00. I need to cover a 376 sq ft area. I need to know which is the best deal and how much I need to buy to cover the 376 sq ft. Thanks, Dianna Hi Dianna.

1 cubic yard = 1 (yard)3. Since each yard = 3 feet, 1 cubic yard = 1 (3 feet)3 = 27 feet3. So a cubic yard is 27 cubic feet.

The first price is $25 for 27 cubic feet, so that works out to$0.93 per cubic foot.

Walmart's price is $3 for 2 cubic feet, so that works out to$1.50 per cubic foot.

Clearly, by buying in larger quantities you get a better price.

How much to buy depends on the depth you plan. Each inch of depth is 1/12 of a foot, so each inch of depth requires 376/12 = 31.33 cubic feet. Multiply the number of inches by 31.33 to get the number of cubic feet you will need to purchase.

Hope this helps,
Stephen La Rocque.     Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.