A right circular cylinder having diameter 21 cm & height 38 cm is full of ice cream. The ice cream is to be filled in cones of height 12 cm and diameter 7 cm having a hemispherical shape on the top. The number of such cones to be filled with ice cream is

The diameter of a sphere is twice the diameter of another sphere. The surface area of the first sphere is equal to the volume of the second sphere. The magnitude of the radius of the fist sphere is

The lateral surface area of frustum of a right circular cone, if the area of its base is 16∏ cm² and the diameter of circular upper surface is 4 cm and slant height 6 cm, will be

A solid cylinder has the total surface area 231 sq. cm. If its curved surface area is 2/3 of the total surface area, then the volume of the cylinder is

A rectangular water tank is 80 m x 40 m. Water flows into it through a pipe of 40 sq.cm at the opening at a speed of 10 km/hr. The water level will rise in the tank in half an hour is

A hemispherical bowl of internal radius 9 cm, contains a liquid. This liquid is to filled into small cylindrical bottles of diameter 3 cm and height 4 cm. Then the number of bottles necessary to empty the bowl is