Advertisements
Advertisements
Question
Three equal cubes are placed adjacently in a row. Find the ratio of total surface area of the new cuboid to that of the sum of the surface areas of the three cubes.
Advertisements
Solution
Length of new cuboid= 3a
Breadth of cuboid=a
Height of new cuboid= a
The total surface area of new cuboid
`⇒(TSA)_1= 2[lb+bh+hl]`
`⇒(TSA)_1=2[3axxa+axxa+3axxa]`
`⇒(TSA)= 14 a^2`
Total surface area of three cubes
`⇒(TSA)_2=3xx6a^2=18a^2`
`∴(TSA)_2/(TSA_2)=(14a^2)/(18a^2)= 7/9`
`Ratio is 7:9`
APPEARS IN
RELATED QUESTIONS
A cuboidal block of solid iron has dimensions 50 cm, 45 cm and 34 cm. How many cuboids of size 5 cm by 3 cm by 2 cm can be obtained from this block? Assume cutting causes no wastage.
A cuboidal box is 5 cm by 5 cm by 4 cm. Find its surface area.
Show that the product of the areas of the floor and two adjacent walls of a cuboid is the square of its volume.
The number of cubes of side 3 cm that can be cut from a cuboid of dimensions 10 cm × 9 cm × 6 cm, is ______.
The volume of a cuboid is 7.68 m3. If its length = 3.2 m and height = 1.0 m; find its breadth.
Find the volume of wood required to make a closed box of external dimensions 80 cm, 75 cm, and 60 cm, the thickness of walls of the box being 2 cm throughout.
A room is 22m long, 15m broad and 6m high. Find the area of its four walls and the cost of painting including doors and windows at the rate of Rs.12per m2.
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?
Opposite faces of a cuboid are ______ in area.
