3. A cylindrical vessel of height 5 cm and radius 4 cm is completely filled with sand. When this sand is poured out it forms a right circular cone of radius 6 cm. What will be the height of this cone? (Take ? = 22/7)
7. If a cylinder of radius 4.3 cm and height 4.8 cm is melted and constructed into a cone of the same radius, what will be the height of this cone? (Use ? = 22/7)