Hi Joe,

First you need to know the number of square yards in an acre. I asked Google. When you type 1 acre in square yards into the Google search window you get the reply tat 1 acre is 4840 square yards. Thus your 10 acres of land is 48,400 square yards. If you spread soil to a depth of $d$ yards over this 10 acres then the volume of soil will be $48,400 \times d$ cubic yards. But you know this volume is 54,000 cubic yards so

\[d = \frac{54000}{48400} = 1.12 \mbox{ yards.}\]

There are 36 inches in a yard so that is $1.12 \times 36$ inches.

Penny