Question

A student of your school become the captain
in Indian navy. He has won several
awards, He is been invited has chief guest
of your Annual day, write 10 questions you
will ask him at the interview​

Answer 1

Answer:

Given:

CSA of cylinder = 440 cm

Height = 21 cm

To find:

➜ Volume = ?

Method:

\begin{gathered}\large{\sf{\star \: CSA \: of\: cylinder = 2 \pi r h}}\\\\\\\Rightarrow \sf{440 = 2 \times \dfrac{22}{7} \times r \times 21}\\\\\\\Rightarrow \sf{440 = 2 \times 22 \times 3r}\\\\\\\Rightarrow \sf{440 = 132r}\\\\\\\Rightarrow \sf{r = \dfrac{440}{132}}\\\\\\\therefore \underline{\bf{r = 3.3 \: cm}}\end{gathered}

⋆CSAofcylinder=2πrh

⇒440=2×

7

22

×r×21

⇒440=2×22×3r

⇒440=132r

⇒r=

132

440

∴

r=3.3cm

\rm{Now \: let's \: find \: volume;}Nowlet

′

sfindvolume;

\begin{gathered}\large{\sf{Volume\: of\: cylinder = \pi r^{2}h}}\\\\\\\Rightarrow \sf{Volume = \dfrac{22}{7} \times (3.3)^{2} \times 21}\\\\\\\Rightarrow \sf{Volume = \dfrac{22}{7} \times 10.89 \times 21}\\\\\\\Rightarrow \sf{Volume = 22 \times 10.89 \times 3}\\\\\\\therefore \boxed{\bf{Volume = 718.74 \: cm}}\end{gathered}

Volumeofcylinder=πr

2

h

⇒Volume=

7

22

×(3.3)

2

×21

⇒Volume=

7

22

×10.89×21

⇒Volume=22×10.89×3

∴

Volume=718.74cm

Additional Information:

\begin{gathered}\begin{array}{|c|c|c|}\cline{1-3}\bf Shape&\bf Volume\ formula&\bf Surface\ area formula\\\cline{1-3}\sf Cube&\tt l^3}&\tt 6l^2\\\cline{1-3}\sf Cuboid&\tt lbh&\tt 2(lb+bh+lh)\\\cline{1-3}\sf Cylinder&\tt {\pi}r^2h&\tt 2\pi{r}(r+h)\\\cline{1-3}\sf Hollow\ cylinder&\tt \pi{h}(R^2-r^2)&\tt 2\pi{rh}+2\pi{Rh}+2\pi(R^2-r^2)\\\cline{1-3}\sf Cone&\tt 1/3\ \pi{r^2}h&\tt \pi{r}(r+s)\\\cline{1-3}\sf Sphere&\tt 4/3\ \pi{r}^3&\tt 4\pi{r}^2\\\cline{1-3}\sf Hemisphere&\tt 2/3\ \pi{r^3}&\tt 3\pi{r}^2\\\cline{1-3}\end{array}\end{gathered}