Question 138963
The volume of a sphere is {{{(4/3)pi*r^3}}}, so the volume of the scoop of ice cream, presuming a VERY TIDY person serving the ice cream who invariably makes his/her ice cream scoops into absolutely perfect spheres, is {{{(4/3)pi*2.1^3}}} (If the diameter is 4.2, the radius must be 2.1).  The volume of a right circular cone is 1/3 that of a right circular cylinder with the same base radius and height, so {{{(pi*r^2h)/3}}}.  For the given cone: {{{(pi*2^2*6)/3=pi*2^2*2=pi*2^3}}}.  Don't forget to take some napkins.