Question

Selim is ordering concrete spheres to place as barriers in the city park. The spheres cost $2 per square foot, and Selim can spend $20 per sphere. What is the maximum diameter of the spheres he can purchase?

Answer 1

1.78 feet.

Explanation:

If they cost $20 each and its $2 per square foot, the area of the spheres

is 20 / 2 = 10 ft^2.

Area of sphere = 4 π r^2 = 10 (where r = the radius)

---> r^2 = 10 / 4π

= 0.796

---> r = 0.892 ft

So the diameter = 2 * r

= 1.78 feet to nearest hundredth.