In the given figure, height of the conical part is 3 cm. The radius and the height of the cylindrical part are 1 cm each. The total volume of the body is :

1. 9π cm³

2. 18π cm³

3. 2π cm³

4. 4π cm³

The given figure shows a solid cylinder of height h cm and radius r cm. If the slant height of the conical cavity is l cm, the total surface area of the remaining solid is :

1. πrl + 2πrh + 2πr²

2. πr² + πrl + 2πrh

3. 2πr² - πrl + 2πrh

4. (πrl + πr²) + 2πr² + 2πrh

The given figure shows a solid sphere and a closed cylindrical container, both having the same heights and same radii. The volume of air left in the cylinder is :

1. 6πr³

2. $\dfrac{3}{2}πr^3$

3. $\dfrac{2}{3}πr^3$

4. 4πr³

A cone of height 15 cm and diameter 7 cm is mounted on a hemisphere of same diameter. Determine the volume of the solid thus formed.