<p>The radii of two cones are in the ratio 2:3 and their volumes are in the ratio 1:3. Then the ratio of their heights is:</p>

Two identical solid cubes of side 5 cm are joined end to end. Then the total surface area of the resulting cuboid is:

A pump can be operated both for filling a tank and for emptying it. The capacity of the tank is 2400 $m^{3}$. The emptying capacity of the pump is 10 $m^{3}$ per minute higher than its filling capacity. Consequently, the pump needs 8 minutes less to empty the tank as to fill it. The filling capacity of the pump is

A 30 meter deep well, with a diameter of 7 meters is dug and the earth from digging is evenly spread out to form a platform of size 22 meters by 14 meters. The height of the platform is:

A solid brass sphere of radius 21 cm is converted into a right circular cylindrical rod of length 28 cm. The ratio of total surface areas of the rod to sphere is :

Floor of a room is $15 \text{ m } 17 \text{ cm}$ long and $9 \text{ m } 2 \text{ cm}$ broad. What is the least number of square tiles required to pave the floor?

If each side of a cube is decreased by $19 \%$, then the decrease in surface area is :