Pz it's urgent tomorrow is my test

Pz it's urgent tomorrow is my test .8

Dear Student,

Please find below the solution to the asked query:

We know : Curved surface area of cylinder = 2$\mathrm{\pi }$rh
So,

CSA of in metal pipe = $2 \times \frac{22}{7} \times 4 \times 77 = 2 \times 22 \times 4 \times 11 = \mathbf{1936}\mathbf{ }{\mathbf{cm}}^{\mathbf{2}}\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{(}\mathbf{ }\mathbf{Ans}\mathbf{ }\mathbf{)}$

CSA of in metal pipe = $2 \times \frac{22}{7} \times 4.8 \times 77 = 2 \times 22 \times 4.8 \times 11 = \mathbf{2323}\mathbf{.}\mathbf{2}\mathbf{ }{\mathbf{cm}}^{\mathbf{2}}\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{(}\mathbf{ }\mathbf{Ans}\mathbf{ }\mathbf{)}$

And

We know total surface area of hollow cylinder = 2 $\mathrm{\pi }$ ( R + r ) ( R - r + h ) , So

TSA of metal pipe = $2 \times \frac{22}{7}\times \left(4.8 +\hspace{0.17em}4\right) \times \left(4.8 - 4 + 77\right) = 2 \times \frac{22}{7}\times 8.8 \times 77.8 = \mathbf{30124}\mathbf{.}\mathbf{16}\mathbf{ }{\mathbf{cm}}^{\mathbf{2}}\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\mathbf{ }\left(\mathbf{ }\mathbf{Ans}\mathbf{ }\right)$

Hope this information will clear your doubts about topic.

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