math
posted by kayla .
a pool in the shape of a circle measures 10 feet across. One cubic yard of concrete is used to create a circular border of uniform width around the pool. If the border is to have a depth of 3 inches, how wide will the border be (1 cubic yard=27 cubic feet)

area of border= (outerradius^2innerradius^2) * PI
27= 1/4 ft*area border
solve for outerradius.