How many silver coins,$1.75 \,cm$ in diameter and of thickness $2 \,mm$,must be melted to form a cuboid of dimensions $5.5 \,cm \times 10 \,cm \times 3.5 \,cm$? [Take $\pi = \frac{22}{7}$]

$A$ cone of height $24\, cm$ and radius of base $6\, cm$ is made up of modelling clay. $A$ child reshapes it in the form of a sphere. Find the radius of the sphere (in $cm$).

From a solid cylinder whose height is $2.4 \, cm$ and diameter is $1.4 \, cm$,a conical cavity of the same height and same diameter is hollowed out. Find the total surface area of the remaining solid to the nearest $cm^2$. [Take $\pi = \frac{22}{7}$]

$A$ copper wire,$3 \,mm$ in diameter,is wound about a cylinder whose length is $12 \,cm$ and diameter $10 \,cm$,so as to cover the curved surface of the cylinder. Find the mass of the wire,assuming the density of copper to be $8.88 \,g/cm^3$. (in $g$)

An open metal bucket is in the shape of a frustum of a cone,mounted on a hollow cylindrical base made of the same metallic sheet (see figure). The diameters of the two circular ends of the bucket are $45 \, cm$ and $25 \, cm$,the total vertical height of the bucket is $40 \, cm$ and that of the cylindrical base is $6 \, cm$. Find the area of the metallic sheet used to make the bucket,where we do not take into account the handle of the bucket. Also,find the volume of water the bucket can hold. (Take $\pi = \frac{22}{7}$)

Selvi's house has an overhead tank in the shape of a cylinder. This is filled by pumping water from a sump (an underground tank) which is in the shape of a cuboid. The sump has dimensions $1.57 \, m \times 1.44 \, m \times 95 \, cm$. The overhead tank has a radius of $60 \, cm$ and a height of $95 \, cm$. Find the height of the water left in the sump after the overhead tank has been completely filled with water from the sump which had been full. Compare the capacity of the tank with that of the sump. (Use $\pi = 3.14$)