मराठी
सी.आई.एस.सी.ई.आयसीएसई ICSE Class 8

The Length, Breadth, and Height of a Cuboid Are in the Ratio 5 : 3: 2. If Its Volume is 240 Cm3; Find Its Dimensions. Also, Find the Total Surface Area of the Cuboid. - Mathematics

Advertisements
Advertisements

प्रश्न

The length, breadth, and height of a cuboid are in the ratio 5 : 3: 2. If its volume is 240 cm3; find its dimensions. Also, find the total surface area of the cuboid.

बेरीज
Advertisements

उत्तर

Let length of the given cuboid = 5x

Breadth of the given cuboid = 3x

Height of the given cuboid = 2x

Volume of the given cuboid = Length x Breadth x Height
= 5x x 3x x 2x = 30x3

But we are given volume = 240 cm3

30x3 = 240 cm3

⇒ x3 = `240/30`

⇒ x3 = 8

⇒ x = `8^(1/3)`  

⇒ x = `(2 xx 2 xx 2)^(1/3)`

⇒ x = 2 cm

Length of the given cube = 5x = 5 x 2 = 10 cm

Breadth of the given cube = 3x = 3 x 2 = 6 cm

Height of the given cube = 2x = 2 x 2 = 4cm

Total surface area of the given cuboid = 2(l x b + b x h + h x l)

= 2(10 x 6 + 6 x 4 + 4 x 10) = 2(60 + 24 + 40) = 2 x 124

= 248 cm2

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 21: Surface Area, Volume and Capacity - Exercise 21 (A) [पृष्ठ २३८]

APPEARS IN

सेलिना Concise Mathematics [English] Class 8 ICSE
पाठ 21 Surface Area, Volume and Capacity
Exercise 21 (A) | Q 3 | पृष्ठ २३८

संबंधित प्रश्‍न

The floor of a rectangular hall has a perimeter 250 m. If the cost of panting the four walls at the rate of Rs.10 per m2 is Rs.15000, find the height of the hall.

[Hint: Area of the four walls = Lateral surface area.]


A small indoor greenhouse (herbarium) is made entirely of glass panes (including base) held together with tape. It is 30 cm long, 25 cm wide and 25 cm high. How much of tape is needed for all the 12 edges?


Shanti Sweets Stall was placing an order for making cardboard boxes for packing their sweets. Two sizes of boxes were required. The bigger of dimensions 25 cm × 20 cm × 5 cm and the smaller of dimensions 15 cm × 12 cm × 5 cm. For all the overlaps, 5% of the total surface area is required extra. If the cost of the cardboard is Rs 4 for 1000 cm2, find the cost of cardboard required for supplying 250 boxes of each kind.


There are two cuboidal boxes as shown in the adjoining figure. Which box requires the lesser amount of material to make?

(a) (b)

Find the ratio of the total surface area and lateral surface area of a cube.


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.


The paint in a certain container is sufficient to paint on area equal to 9.375 m2. How manybricks of dimension 22.5 cm × 10 cm × 7.5 cm can be painted out of this container?


Find the volume of a cuboid whose length = 15 cm, breadth = 2.5 dm, height = 8 cm.


A cuboidal vessel is 10 cm long and 5 cm wide. How high it must be made to hold 300 cm3 of a liquid?


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.


Find the weight of solid rectangular iron piece of size 50 cm × 40 cm × 10cm, if 1 cm3 of iron weighs 8 gm.


An ice-cream brick measures 20 cm by 10 cm by 7 cm. How many such bricks can be stored in deep fridge whose inner dimensions are 100 cm by 50 cm by 42 cm?


What will be the height of a cuboid of volume 168 m3, if the area of its base is 28 m2?


Find the length of the longest rod that can be placed in a room 12 m long, 9 m broad and 8 m high.


Find the edge of a cube whose surface area is 432 m2.

 

If the perimeter of each face of a cube is 32 cm, find its lateral surface area. Note that four faces which meet the base of a cube are called its lateral faces.


A cuboid has total surface area of 372 cm2 and its lateral surface area is 180 cm2, find the area of its base.


Three equal cubes are placed adjacently in a row. The ratio of the total surface area of the resulting cuboid to that of the sum of the surface areas of three cubes, is


If each edge of a cube, of volume V, is doubled, then the volume of the new cube is


The sum of the length, breadth and depth of a cuboid is 19 cm and its diagonal is ` 5 sqrt(5)` cm. Its surface area is


If l is the length of a diagonal of a cube of volume V, then


Total surface area of a box of cuboid shape is 500 sq. unit. Its breadth and height is 6 unit and 5 unit respectively. What is the length of that box ?


The breadth and height of a rectangular solid are 1.20 m and 80 cm respectively. If the volume of the cuboid is 1.92 m3; find its length.


The length, breadth, and height of a cuboid are in the ratio 6: 5 : 3. If its total surface area is 504 cm2; find its dimensions. Also, find the volume of the cuboid.


A room is 5m long, 2m broad and 4m high. Calculate the number of persons it can accommodate if each person needs 0.16m3 of air.


Find the volume of wood used in making a closed box 22 cm by 18 cm by 14 cm, using a 1 cm thick wood. Also, find the cost of wood required to make the box at the rate of Rs. 5 per cm³ How many cubes of side 2 cm can be placed in the box?


An aquarium is in the form of a cuboid whose external measures are 80 cm × 30 cm × 40 cm. The base, side faces and back face are to be covered with a coloured paper. Find the area of the paper needed?

Opposite faces of a cuboid are ______ in area.


Two cuboids with equal volumes will always have equal surface areas.


A rectangular sheet of dimensions 25 cm × 7 cm is rotated about its longer side. Find the volume and the whole surface area of the solid thus generated.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×