A corn cob (see in figure), shaped somewhat like a cone, has the radius of its broadest end as 2.1 cm and length as 20cm. If each `1\ c m^2` of the surface of the cob carries an average of four grains, find how many grains you would find on the entire cob?

A corn cob (see Fig. 13.17), shaped somewhat like a cone, has the radius of its broadest end as 2.1 cm and length (height) as 20 cm. If each 1 cm^2 of the surface of the cob carries an average of four grains, find how many grains you would find on the entire cob?

The area of a rectangle is 240\ c m^2dot If its length is 20cm, find its breadth.

The radius of a cone 7cm and area of curved surface is 176\ c m^2 . Find the slant height.

Find the area of a circle whose radius is (a)7 cm (b) 2.1 m (c)7 km

Hanumappa and his wife Gangavva are busy making Jaggery out of sugar-cane. They have processed the sugarcane juice to make the molasses which is poured into moulds of the shape shown in Figure. It will be cooled to solidify in this shape to be sent to the market. Each mould is in the shape of a frustum of a cone having the diameters of its two circular ends as 30 cm and 35 cm and the height of the mould is 14 cm. If each c m^3 of molasses weighs about 1.2 gm, find the weight of molasses that can be poured into each mould (Take pi=22//7 )

Curved surface area of a cone is 308\ c m^2 and its slant height is 14cm. Find the radius of the base and total surface area of the cone.

Curved surface area of a cone is 308\ c m^2 and its slant height is 14cm. Find the radius of the base and total surface area of the cone.

A biconvex lens (mu=1.5) has radius of curvature 20cm (both). find its focal length.

The area of the curved surface of a cone is 60pi\ c m^2dot If the slant height of the cone be 8cm, find the radius of the base.

Curved surface area of a cone is 308\ c m^2 and its slant height is 14 cm. Find (i) radius of the base and (ii) total surface area of the cone.