Hi Steve,
Since you want the volume in cubic yards you should change all the units to yards. There are 3 feet in a yard so
30 feet is 30/3 = 10 yards and
60 feet is 60/3 = 20 yards.
There are 36 inches in a yard so
1/4 inches is 1/(4 36) = 1/144 yards
Thus the volume of sand you need is
10 20 1/144 = 1.4 cubic yards.
Penny
