Let r1​ and r2​ be the intenal and external base radi of spherical shell.r1​=3cm, and r2​=5cm.Base radius of a solid cylinder, r=7cmLet the height of the cylinder =hAs per given statement:The hollow spherical shell is melted into a solid cylinder, so the volume of solid cylinder = volume of a spherical shell πr2h =34​ π (r23​−r13​) 49h=34​(125−27) h=38​cm