A conical vessel whose internal radius is 10 cm and height 48 cm is full of water. If this water is poured into a cylindrical vessel with internal radius 20 cm, the height to which water rises in it is:

(Take π = 3.14)

1. 3 cm

2. 4 cm

3. 5 cm

4. 6 cm

A cylindrical vessel 32 cm high and 18 cm as the radius of the base, is filled with sand. This bucket is emptied on the ground and a conical heap of sand is formed. If the height of the conical heap is 24 cm, the radius of its base is :

1. 12 cm

2. 24 cm

3. 36 cm

4. 48 cm

If the ratio of volumes of two spheres is 1 : 8, then the ratio of their surface areas is :

1. 1 : 2

2. 1 : 4

3. 1 : 8

4. 1 : 16