The outer diameter of a drainage pipe is 105cm and it is 32 m long. Find the cost of painting the outer the surface of the pipe at the rate of rupees 7 per m square
Answers
Answer:
In the questions given
The outer diameter of drainage pipe is 105cm.
\begin{gathered}r = \frac{d}{2} \\ \\ r = \frac{105}{2} \\ \\ r = 52.5cm\end{gathered}
r=
2
d
r=
2
105
r=52.5cm
Change in meter
\begin{gathered} \frac{52.5}{100} \\ \\ 0.525m\end{gathered}
100
52.5
0.525m
Length is equal to 32 m.
CSA = 2 πr h sq units
\begin{gathered}2 \times \frac{22}{7} \times 0.525 \times 32 \\ \\ 2 \times \frac{22}{7} \times \frac{525}{1000} \times 32\end{gathered}
2×
7
22
×0.525×32
2×
7
22
×
1000
525
×32
\begin{gathered}64 \times \frac{11550}{7000} \\ \\ \frac{739200}{7000} \\ \\ 105.6 {m}^{2} \end{gathered}
64×
7000
11550
7000
739200
105.6m
2
In the questions given,
1 {m}^{2} cost \: of \: colouring \: 7 Rs .1m
2
costofcolouring7Rs.
Then
\begin{gathered}105 .6{m}^{2} cost \: of \: colouring \: \\ \\ = 105.6 \times 7\end{gathered}
105.6m
2
costofcolouring
=105.6×7
739.20 Rs .
Therefore the cost of painting the outer the surface of the pipe is equal to 739.20 Rs .