A conical tent is to accomodate 11 persons such that each person occupies 4 m² space on the ground and has 20 m³ of air to breathe. The height of the cone is :

1. 14 m

2. 15 m

3. 16 m

4. 20 m

The diameters of two cones are equal. If their slant heights are in the ratio 5 : 4 the ratio of their curved surface areas is:

1. 4 : 5

2. 5 : 4

3. 16 : 25

4. 25 : 16

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