Question

a metallic pipe has internal diameter 14 cm and thickness 0.5 cm if 1cm³ of the material has mass 10 gm find the mass of 28 cm long pipe​

Answer 1

Step-by-step explanation:

Question 1

Given :-

Perimeter of rectangle= 240cm

Length of rectangle 40cm

To Find :-

We have to find the Area of rectangle

Solution:-

Let the breadth of rectangle be x

Now first find the breadth then the area

\begin{gathered}\underline{\blue{\sf\ Perimeter\ of\ Rectangle= 2(l+b)}}\\ \\ \\ :\implies\sf\ 240= 2(40+x)\\ \\ \\ :\implies\sf\ \cancel{\dfrac{240}{2}}= 40+x\\ \\ \\ :\implies\sf\ 120=40+x\\ \\ \\ :\implies\sf\ 120-40=x\\ \\ \\ :\implies\sf\ 80=x\\ \\ \\ \therefore{\purple{\sf\ Breadth=80cm}}\end{gathered}

Perimeter of Rectangle=2(l+b)

:⟹ 240=2(40+x)

:⟹

2

240

=40+x

:⟹ 120=40+x

:⟹ 120−40=x

:⟹ 80=x

∴ Breadth=80cm

Now Area of rectangle

\begin{gathered}\underline{\boxed{\sf\ Area\ of\ Rectangle= \ell \times b}}\\ \\ \\ :\implies\sf\ Area= 80\times 40\\ \\ \\ :\implies\sf\ Area= 3200cm^2\end{gathered}

Area of Rectangle=ℓ×b

:⟹ Area=80×40

:⟹ Area=3200cm

2

\underline{\textsf{\textbf{\ Area\ of\ Rectangle= 3200cm}}^2}

Area of Rectangle= 3200cm

2

\underline{\it\ Question \ 2}

Question 2

Let the total quantity be a

Now 7% of a =490

We have to find the value of a

Solution :-

\begin{gathered}:\implies\sf\ 7\%\ of\ a= 490\\ \\ \\ :\implies\sf\ \dfrac{7}{100}\times \ a= 490\\ \\ \\ :\implies\sf\ a= \dfrac{\cancel{490}\times 100}{\cancel{7}}\\ \\ \\ :\implies\sf\ a= 70\times 100\\ \\ \\ :\implies\underline{\boxed{\sf{\red{\ a= 7000}}}}\end{gathered}

:⟹ 7% of a=490

:⟹

100

7

× a=490

:⟹ a=

7

490

×100

:⟹ a=70×100

:⟹

a=7000