Find the total surface area of a hemisphere of radius $10 \, cm.$ (Use $\pi = 3.14$) (in $cm^2$)

$A$ metal pipe is $77 \, cm$ long. The inner diameter of a cross section is $4 \, cm$ and the outer diameter is $4.4 \, cm$ (see Fig.). Find its total surface area. (in $, cm^2$)

Shanti Sweets Stall was placing an order for making cardboard boxes for packing their sweets. Two sizes of boxes were required. The bigger of dimensions $25 \,cm \times 20 \,cm \times 5 \,cm$ and the smaller of dimensions $15 \,cm \times 12 \,cm \times 5 \,cm$. For all the overlaps,$5\%$ of the total surface area is required extra. If the cost of the cardboard is $Rs. 4$ for $1000 \,cm^2$,find the cost of cardboard required for supplying $250$ boxes of each kind.

Curved surface area of a right circular cylinder is $4.4 \, m^2$. If the radius of the base of the cylinder is $0.7 \, m$,find its height. (Take $\pi = \frac{22}{7}$) (in $, m$)

$A$ child is playing with building blocks, which are in the shape of cubes, and has built a structure as shown in the figure. If the edge of each cube is $3 \, cm$, find the volume of the structure built by the child. (in $cm^3$)

Diameter of the base of a cone is $10.5\, cm$ and its slant height is $10\, cm$. Find its curved surface area. Assume $\pi = \frac{22}{7}$. (in $, cm^2$)