English

Three Cuboids of Dimensions 5 Cm × 6 Cm × 7cm, 4cm × 7cm × 8 Cm and 2 Cm × 3 Cm × 13 Cm Are Melted and a Cube is Made. Find the Side of Cube. - Mathematics

Advertisements
Advertisements

Question

Three cuboids of dimensions 5 cm × 6 cm × 7cm, 4cm × 7cm × 8 cm and 2 cm × 3 cm × 13 cm are melted and a cube is made. Find the side of cube.

Answer in Brief
Advertisements

Solution

\[\text { The dimensions of the three cuboids are 5 cm  }\times 6 cm \times 7 cm, 4 cm \times 7 cm \times 8 cm \text { and } 2 cm \times 3 cm \times 13 cm . \]

\[\text { Now, a new cube is formed by melting the given cuboids }. \]

\[ \therefore \text { Voulume of the cube = sum of the volumes of the cuboids }\]

\[ = (5 cm \times 6 cm \times 7 cm) + (4 cm \times 7 cm \times 8 cm) + (2 cm \times 3 cm \times 13 cm)\]

\[ = (210 {cm}^3 ) + (224 {cm}^3 ) + (78 {cm}^3 )\]

\[ = 512 {cm}^3 \]

\[\text { Since volume of a cube = (side ) }^3 , \text { we have }: \]

\[512 =\text {  (side ) }^3 \]

\[ \Rightarrow (\text { side) } = \sqrt[3]{512} = 8 cm\]

\[ \therefore \text { The side of the new cube is 8 cm } .\]

shaalaa.com
  Is there an error in this question or solution?
Chapter 21: Mensuration - II (Volumes and Surface Areas of a Cuboid and a Cube) - Exercise 21.1 [Page 8]

APPEARS IN

RD Sharma Mathematics [English] Class 8
Chapter 21 Mensuration - II (Volumes and Surface Areas of a Cuboid and a Cube)
Exercise 21.1 | Q 9 | Page 8

RELATED QUESTIONS

Parveen wanted to make a temporary shelter for her car, by making a box-like structure with tarpaulin that covers all the four sides and the top of the car (with the front face as a flap which can be rolled up). Assuming that the stitching margins are very small, and therefore negligible, how much tarpaulin would be required to make the shelter of height 2.5 m, with base dimensions 4 m × 3 m?


An open box is made of wood 3 cm thick. Its external length, breadth and height are 1.48 m, 1.16 m and 8.3 m. Find the cost of painting the inner surface of Rs 50 per sq. metre.


Find the volume of a cuboid whose  length =1.2 m, breadth = 30 cm, height = 15 cm.


The length , breadth and height of a room are 5 m, 4.5 m and 3 m, respectively. Find the volume of the air it contains.


A cloassroom is 11 m long, 8 m wide and 5 m high. Find the sum of the areas of its floor and the four walls (including doors, windows, etc.)


If the sum of all the edges of a cube is 36 cm, then the volume (in cm3) of that cube is


In a building, there are 24 cylindrical pillars. For each pillar, the radius is 28 m, and the height is 4 m. Find the total cost of painting the curved surface area of the pillars at the rate of ₹ 8 per m2.


An open box of length 1.5 m, breadth 1 m, and height 1 m is to be made for use on a trolley for carrying garden waste. How much sheet metal will be required to make this box? The inside and outside surface of the box is to be painted with rust-proof paint. At a rate of 150 rupees per sqm, how much will it cost to paint the box?


The dimensions of a hall is 10 m × 9 m × 8 m. Find the cost of white washing the walls and ceiling at the rate of ₹ 8.50 per m2 


Find the capacity of water tank, in litres, whose dimensions are 4.2 m, 3 m and 1.8 m?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×