Question

The height and base radius of a cone is 14 cm and 6 cm respectively is carved from
rectangular block of wood of dimension 20 cm x 10 cm x 4 cm. Find the percentage of wood
wasted.​

Answer 1

Here Radius of Cone = 3 cm and Height is 7 cm

Volume of cone = 1/3 (πr²h)

                          \frac{1}{3} \times \frac{22}{7} \times 3 \times 3 \times 7 = 66 cm^231×722×3×3×7=66cm2

Volume of cuboid block = L × B × H

                                        = (10 × 5 × 2) cm³

                                        = 100 cm³

Wood Wasted = Volume of Cuboid Block - Volume of Cone

                       = 100 cm³ - 66 cm³

                       = 34 cm³

Percentage of wood wasted = (wasted wood / volume of cuboid block) ×100

                                              = (34/100)×100

                                             = 34%

∴ 34% wood was wasted.