The length, breadth and height of a room is 21 metres, 12 metres and 16 metres. What will be the length of the largest rod that can be placed in that room?

A solid metallic cylinder of base radius 5 cm and height 7 cm is melted to form cones, each of height 1 cm and base radius 1 mm. Find the number of cones?

A semicircle is folded to make a cone. Find the height (in cm) of the cone if diameter of the semicircle is 28 cm?

50 men took a dip in a water tank 40 m long and 20 m broad on a religious day. If the average displacement of water by a man is $$ {4 m^{3}}$$ , then the rise in the water level in the tank will be:

The area covered by a square is 308 square cm. The length of the diagonal of the square is.

A right triangle with sides 5 cm, 12 cm and   13 cm is rotated about the side 12 cm to from a cone. The volume of the cone so formed is :

From a circle of radius a, a sector, which subtend an angle π/5 at the centre has been cut off. The perimeter of the remaining part of the circle is

In a circle of radius 17 cm, two parallel chords of lengths 30 cm. and 16 cm are drawn. If both the chords are on the same side of the center, then the distance between the chords is -