Ex 9.3

Chapter 9 Class 8 Mensuration
Serial order wise

### Transcript

Ex 9.3, 4 A cuboid is of dimensions 60 cm × 54 cm × 30 cm. How many small cubes with side 6 cm can be placed in the given cuboid?Given, Length of cuboid = l = 60 cm Breadth = b = 54 cm & Height = h = 30 cm Also, Side of cube = 6 cm Now, Cube is placed in the cuboid So, Volume of cuboid = Number of cubes × Volume of 1 cube Number of cubes = (𝑽𝒐𝒍𝒖𝒎𝒆 𝒐𝒇 𝒄𝒖𝒃𝒐𝒊𝒅)/(𝑽𝒐𝒍𝒖𝒎𝒆 𝒐𝒇 𝟏 𝒄𝒖𝒃𝒆) Volume of cuboid Volume = 𝑙 × 𝑏 × ℎ = 𝟔𝟎 × 𝟓𝟒 × 𝟑𝟎 = 6 × 54 × 3 × 100 = 18 × 54 × 100 = 972 × 100 = 𝟗𝟕𝟐𝟎𝟎 cm3 Volume of cube Volume = (Side)3 = 6 × 6 × 6 = 𝟐𝟏𝟔 cm3 Now, Number of cubes = (𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑐𝑢𝑏𝑜𝑖𝑑)/(𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 1 𝑐𝑢𝑏𝑒) = 𝟗𝟕𝟐𝟎𝟎/𝟐𝟏𝟔 = 16200/36 = 2700/6 = 450 ∴ 450 small cubes can be placed in cuboid.

#### Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.