A cone of height 7 cm and base radius 3 cm is carved from a rectangular block of wood 10 cm × 5 cm × 2 cm. The percentage of wood wasted is:

1. 34%

2. 46%

3. 54%

4. 66%

An edge of a cube measures 10 cm. If the largest possible right circular cone is cut out of this cube, then the volume of the cone is:

1. 260 cm³

2. 260.9 cm³

3. 261.9 cm³

4. 262.7 cm³

If the height of two cones are in the ratio of 1 : 4 and the radii of their bases are in the ratio 4 : 1, then the ratio of their volumes is:

1. 1 : 2

2. 2 : 3

3. 3 : 4

4. 4 : 1

If the volumes of two cones are in the ratio of 1 : 4 and their diameters are in the ratio 4 : 5, then the ratio of their heights is :

1. 1 : 5

2. 5 : 4

3. 5 : 16

4. 25 : 64