Trigonometry
posted by Joyce .
a man has three golden spheres with radius 1mm,2mm,3mm,respectively. He plans to melt it and make a larger sphere. What will be the radius of the larger sphere?

volume of 3 spheres
= (4/3)π( 1^3 + 2^3 + 3^3)
=(4/3)π(36)
= 48π
then for new sphere
(4/3)π r^3 = 48π
r^3 = 36
r = (36)^(1/3) = appr. 3.3