Advertisements
Advertisements
प्रश्न
If each edge of a cube is increased by 50%, the percentage increase in its surface area is
पर्याय
50%
75%
100%
125%
Advertisements
उत्तर
Let,
a →a Initial edge of the cube
A → Initial surface area of the cube
a' → Increased edge of the cube
A' → Increased surface area of the cube
We have to find the percentage increase in the surface area of the cube
Since it’s given that
`a = a+axx50/100`
`= 3/2 a`
We have,
`A' = 6(a)^2`
`= 6 (3/2a)^2 { Since , a' = 3/2 a}`
` = 9/4 (6a^2)`
` =9/4 A`
Percentage increase in surface area,
`=(A'-A)/A xx 100`
`=(9/4 A-A)/A xx 100`
`=(5/4A)/A xx 100`
= 125
Increase in surface area is 125% .
APPEARS IN
संबंधित प्रश्न
There are two cuboidal boxes as shown in the adjoining figure. Which box requires the lesser amount of material to make?
 |
 |
| (a) | (b) |
A 4 cm edge cube is cut into 1 cm edge cubes. Calculate the total surface area of all the small cubes.
Find the volume of a cuboid whose length =1.2 m, breadth = 30 cm, height = 15 cm.
A swimming pool is 250 m long and 130 m wide. 3250 cubic metres of water is pumped into it. Find the rise in the level of water.
If the length of a diagonal of a cube is `8 sqrt(3)` cm, then its surface area is
Find the volume and the total surface area of a cuboid, whose :
length = 15 cm, breadth = 10 cm and height = 8 cm.
Four cubes, each of edge 9 cm, are joined as shown below :
Write the dimensions of the resulting cuboid obtained. Also, find the total surface area and the volume
The length, breadth, and height of a cuboid (rectangular solid) are 4 : 3: 2.
(i) If its surface area is 2548 cm2, find its volume.
(ii) If its volume is 3000 m3, find its surface area.
The floor of a rectangular hall has a perimeter 250 m. If the cost of painting the four walls at the rate of ₹ 10 per m2 is ₹ 15,000, find the height of the hall.
The dimensions of a cuboidal box are 6 m × 400 cm × 1.5 m. Find the cost of painting its entire outer surface at the rate of ₹ 22 per m2.
