Advertisements
Advertisements
Question
The length of a hall is 18 m and the width 12 m. The sum of the areas of the floor and the flat roof is equal to the sum of the areas of the four walls. Find the height of the wall.
Advertisements
Solution
\[\text { Length of the hall = 18 m }\]
\[ \text { Its width = 12 m } \]
\[\text { Suppose that the height of the wall is h m } . \]
\[\text { Also, sum of the areas of the floor and the flat roof = sum of the areas of the four walls } \]
\[ \Rightarrow 2 \times\text { (length }\times \text { breadth)
}= 2 \times \ \text { (length + breadth) }\times \text { height }\]
\[ \Rightarrow 2 \times (18 \times 12) = 2 \times (18 + 12) \times h\]
\[ \Rightarrow 432 = 60 \times h\]
\[ \Rightarrow h = \frac{432}{60} = 7 . 2 m\]
\[ \therefore \text { The height of wall is 7 . 2 m . }\]
APPEARS IN
RELATED QUESTIONS
Mary wants to decorate her Christmas tree. She wants to place the tree on a wooden block
covered with coloured paper with picture of Santa Claus on it. She must know the exact
quantity of paper to buy for this purpose. If the box has length, breadth and height as 80
cm, 40 cm and 20 cm respectively. How many square sheets of paper of side 40 cm would
she require?
A rectangular field is 70 m long and 60 m broad. A well of dimensions 14 m × 8 m × 6 m is dug outside the field and the earth dug-out from this well is spread evenly on the field. How much will the earth level rise?
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.)
The length, width and height of a rectangular solid are in the ratio of 3 : 2 : 1. If the volume of the box is 48cm3, the total surface area of the box is
If V is the volume of a cuboid of dimensions x, y, z and A is its surface area, then `A/V`
Find the area of metal-sheet required to make an open tank of length = 10 m, breadth = 7.5 m and depth = 3.8 m.
The internal length, breadth, and height of a closed box are 1 m, 80 cm, and 25 cm. respectively. If its sides are made of 2.5 cm thick wood; find :
(i) the capacity of the box
(ii) the volume of wood used to make the box.
The length of a cold storage is double its breadth. Its height is 3m. The area of its four walls including doors is 108m2. Find its volume.
A metallic sheet is of the rectangular shape with dimensions 48cm x 36cm. From each one of its corners, a square of 8cm is cutoff. An open box is made of the remaining sheet. Find the volume of the box.
Find the length of the largest pole that can be placed in a room of dimensions 12 m × 4 m × 3 m.
