Advertisements
Advertisements
प्रश्न
The dimensions of a rectangular box are in the ratio of 2 : 3 : 4 and the difference between the cost ofcovering it with sheet of paper at the rates of Rs. 8 and Rs. 9.50 per m2 is Rs.1248. Find the dimensions of the box.
उत्तर
Let the ratio be x
∴length = 2x
Breath = 3x
Height = 4x
∴Total surface area = `2[lb+bh+hl]`
`=2[6x^2+12x^2+8x^2]`
`=52x^2m^2`
When cost is at `Rs. 9.51 per m^2`
`∴Total cost of 52x^2m^2=Rs.8xx52x^2`
`= Rs. 416x^2`
And when the cost is at `95 per m^2`
`∴Total cost of 52x^2m^2=Rs.9.5xx52x^2`
`=Rs.499x^2`
`∴"different in cost"= Rs.494x^2-Rs.416x^2`
`⇒1248=494x^2-416x^2`
`⇒78x^2=1248`
`⇒x^2=16`
`⇒x=4`
APPEARS IN
संबंधित प्रश्न
Water is pouring into a cubiodal reservoir at the rate of 60 litres per minute. If the volume of the reservoir is 108 m3, find the number of hours it will take to fill the reservoir.
Find the ratio of the total surface area and lateral surface area of a cube.
Find the number of cuboidal boxes measuring 2 cm by 3 cm by 10 cm which can be stored in a carton whose dimensions are 40 cm, 36 cm and 24 cm.
The weight of a metal block of size 5 cm by 4 cm by 3 cm is 1 kg. Find the weight of a block of the same metal of size 15 cm by 8 cm by 3 cm.
How many soap cakes can be placed in a box of size 56 cm × 0.4 m × 0.25 m, if the size of a soap cake is 7 cm × 5 cm × 2.5 cm?
If each edge of a cuboid of surface area S is doubled, then surface area of the new cuboid is
Volume of a cuboid is 12 cm3. The volume (in cm3) of a cuboid whose sides are double of the above cuboid is
A room 5 m long, 4.5 m wide, and 3.6 m high have one door 1.5 m by 2.4 m and two windows, each 1 m by 0.75 m. Find :
(i) the area of its walls, excluding door and windows ;
(ii) the cost of distempering its walls at the rate of Rs.4.50 per m2.
(iii) the cost of painting its roof at the rate of Rs.9 per m2.
In a building, there are 24 cylindrical pillars. For each pillar, the radius is 28 m, and the height is 4 m. Find the total cost of painting the curved surface area of the pillars at the rate of ₹ 8 per m2.
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.
