JIPMAT (QA) PYQs

Consider the following statements, which of them is/are correct?

A. If the height of cylinder is doubled, the area of curved surface is doubled.

B. If the radius of a hemispherical solid is doubled, its total surface area becomes fourfold.

C. If a hemisphere and cone have equal bases and equal heights, then the ratio of curved surface area is $\sqrt{2}:1$.

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