(i) The area of the sheet required for making the box.
(ii) The cost of sheet for it, if a sheet measuring 1 m2 costsर 20.
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 ` 15000, find the height of the hall. [Hint : Area of the four walls = Lateral surface area.]
The paint in a certain container is sufficient to paint an area equal to 9.375 m2. How many bricks of dimensions 22.5 cm × 10 cm × 7.5 cm can be painted out of this container?
A cubical box has each edge 10 cm and another cuboidal box is 12.5 cm long, 10 cm wide and 8 cm high.
(i) Which box has the greater lateral surface area and by how much?
A cubical box has each edge 10 cm and another cuboidal box is 12.5 cm long, 10 cm wide and 8 cm high.
(i) Which box has the greater lateral surface area and by how much?
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.
(i) What is the area of the glass?
(ii) How much of tape is needed for all the 12 edges?
For bigger box
l = 25 cm b = 20 cm h = 5 cm
Total surface area of the bigger box
= 2 (lb + bh + hl)
= 2[(25)(20) + (20)(5) + (5)(25)]
= 2[500 + 100 + 125] = 1450 cm2
Cardboard required for all the overlap
∴ Net surface area of the bigger box
= 1450 cm2 + 72.5 cm2 = 1522.5 cm2
∴ Net surface area of 250 bigger boxes
= 1522.5 x 250 = 380625 cm2
Cost of cardboard
For smaller box
l = 15 cm b = 12 cm h = 5 cm
∴ Total surface area of the smaller box = 2 (lb + bh + hl)
= 2[(15)(12) + (12)(5) + (5)( 15)] = 2[ 180 + 60 + 75] = 630 cm2
Cardboard required for all the overlaps
∴ Net surface area of the smaller box
= 630 cm2 + 31.5 cm2 = 661.5 cm2 Net surface area of 250 smaller boxes = 661.5 x250 = 165375 cm2
∴ Cost of cardboard
Cost of cardboard required for supplying 250 boxes of each kind
= र 1522.50 + र 661.50 = र 2184.
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?