Lena is going to cover her entire garden with topsoil. the garden is 36 feet long by 22 feet wide. a bag of topsoil costs $3 and covers 300 square feet of area. how much will the topsoil for lena's garden cost?

So what you first want to find is the area of her garden.

You can do this with the formula length * width

In this case it would be:

36 * 22 

Which is equal to 792.

Now, you just want to find how many bags of topsoil she needs.

Since I'm assuming you cannot buy half of a bag of topsoil, she will end up buying extra topsoil, because you can't just cut a bag of topsoil in half and then take some of it, then buy that.

So to have enough, she must buy 3 bags of top soil, which would end up costing $9.