The radius and height of a cylinder are $1.4 \, cm$ and $10 \, cm$ respectively. Then,its curved surface area is $\ldots \ldots \ldots \, cm^2$.

$A$ wall $24 \, m$ long,$0.4 \, m$ thick and $6 \, m$ high is constructed with bricks each of dimensions $25 \, cm \times 16 \, cm \times 10 \, cm$. If the mortar occupies $\frac{1}{10}$th of the volume of the wall,then find the number of bricks used in constructing the wall.

$A$ solid iron cuboidal block of dimensions $4.4 \, m \times 2.6 \, m \times 1 \, m$ is recast into a hollow cylindrical pipe of internal radius $30 \, cm$ and thickness $5 \, cm$. Find the length of the pipe in meters.

Write 'True' or 'False' and justify your answer:
$A$ solid ball is exactly fitted inside a cubical box of side $a$. The volume of the ball is $\frac{4}{3} \pi a^{3}$.

The radii of a frustum of a cone are $9\, cm$ and $3\, cm$. If its height is $8\, cm$,find its curved surface area and volume. $(\pi=3.14)$

Total surface area of a hemisphere with diameter $2 \, cm$ is $\ldots \ldots \ldots cm^{2}$.