Advertisements
Advertisements
प्रश्न
The diameter of roller 1.5 m long is 84 cm. If it takes 100 revolutions to level a playground, find the cost of levelling this ground at the rate of 50 paise per square metre.
उत्तर
Given that,
Diameter of the roller=84cm=0.84m.
Length of the roller=1.5m
Radius of the roller =`D/2=0.84/2=0.42.`
Area covered by the roller on one revolution = covered surface area of roller
Curved surface of roller= `2pirh=2xx22/7xx0.42xx1.5`
=`0.12xx22xx1.5m^2`
Area of the playground=`"100xxArea covered by roller in one revolution"`
=`(100xx0.12xx22xx1.5)m^2`
=`396m^2`
Now ,
Cost of leveling `1 m^2=50P=50/100⇒Re=1/2rs`
Cost of leveling `396m^2=1/2xx396=Rs.198`
Hence, cost of leveling `396m^2 is 198`
APPEARS IN
संबंधित प्रश्न
The circumference of the base of a cylinder is 88 cm and its height is 15 cm. Find the volume of the cylinder.
The ratio between the radius of the base and the height of a cylinder is 2 : 3. Find the total surface area of the cylinder, if its volume is 1617 cm3.
The trunk of a tree is cylindrical and its circumference is 176 cm. If the length of the trunk is 3 m, find the volume of the timber that can be obtained from the trunk.
A piece of ductile metal is in the form of a cylinder of diameter 1 cm and length 5 cm. It is drawnout into a wire of diameter 1 mm. What will be the length of the wire so formed?
Find the length of 13.2 kg of copper wire of diameter 4 mm, when 1 cubic cm of copper weighs 8.4 gm.
The length of a road roller is 2.1 m and its diameter is 1.4 m. For levelling a ground 500 rotations of the road roller were required. How much area of ground was levelled by the road roller? Find the cost of levelling at the rate of Rs. 7 per sq. m.
Find the area of the sheet required to make a cylindrical container which is open at one side and whose diameter is 28 cm and height is 20 cm. Find the approximate area of the sheet required to make a lid of height 2 cm for this container.
The volume of a solid cylinder is 7700cm3. Find its height and total surface area if the diameter of its base is 35cm.
The total surface area of a cylinder is 3872cm2. Find its height and volume if the circumference of the base is 88cm.
The ratio between the curved surface area and the total surface area of a right circular cylinder is 1 : 2. Find the ratio between the height and radius of the cylinder.
