A solid sphere of radius 3 cm and a cylinder of radius 4 cm and height 3 cm are melted and cast into a cone of slant height 10 cm, such that the sum of the surface area of the sphere and the lateral surface area cylinder equals the lateral surface area of the cone. The height of the cone formed is:
1
8 cm
2
5 cm
3
9 cm
4
7 cm