Twenty seven solid iron sphere, each of radius r and surface area S are melted to form a sphere with surface area S'. Find the
ratio of S and S'.

Twenty seven solid iron sphere, each of radius r and surface area S are melted to form a sphere with surface area S'. Find the radius r' of the new sphere.

Twenty seven solid iron spheres, each of radius r and surface area S aer melted to form a sphere with surface area S^(1). Find the (i) radius r_(1) of the nw sphere (ii) ratio of S and S^(1)

Find the volume of a sphere whose surface area is 154 cm^(2).

The three small metallic spheres of radii in the ratio of 3 :4 :5 are melted to form a big sphere of radius 12 cm . Find the radius of the three small metallic spheres .

A right circular cylinder just encloses a sphere of radius r. Find (i) Durface Area of the sphere (ii) Curved surface area of the cylinder (iii) Ratio of the areas obtained in (i) and (ii)

The surface area of a sphere of radius 7 cm is

Metallic spheres of radii 6cm, 8cm and 10cm , respectively are melted to form a single solid sphere. Find the radius of the resulting sphere.

Find the surface area of a sphere of radius : 5.6 cm

Find the radius of a sphere whose surface area is 154cm^(2).