surface areas

I think you must mean the volume is 250 cm³ not cm²!

 

The minimum surface area is that of a sphere of that volume.  

 

Volume of sphere = (4/3)pi*r³   Set this to 250 cm³ to get the radius, r, in cm.

 

Surface area of sphere = 4pi*r²   Use the radius from the previous step to find the surface area in cm².

 

.