A circus tent is cylindrical to a height of 4 m and conical above it. If its diameter is 105 m and its slant height is 80 m, calculate the total area of canvas required. Also, find the total cost of canvas used at ₹ 15 per meter if the width is 1.5 m.

From a solid cylinder whose height is 16 cm and radius is 12 cm, a conical cavity of height 8 cm and of base radius 6 cm is hollowed out. Find the volume and total surface area of the remaining solid.

The ratio between the heights of two solid cones is 2 : 3 and ratio between their radii is 9 : 8. The ratio between their volumes is :

1. 27 : 32

2. 32 : 27

3. 3 : 2

4. 2 : 3

The radius of a solid cylinder is doubled keeping the height same. The percentage increase in its volume is :

1. 200%

2. 100%

3. 400%

4. 300%