Question

A tank $20$ m long, $12$ m wide and $8$ m deep is to be made. It is open at the top. Determine the cost of iron-sheet, at the rate of Rs. $12.50$ per metre, if the sheet is $2.5$ m wide.

Answer 1

Area of sheet $=$ Surface area of the tank
Surface area of the tank $=$ Area of $4$ walls of the tank $+$ Area of its base
$A=20\times 8+8\times 12+20\times 8+8\times 12+20\times 2$
$A=160+96+160+96+240$
$A=752m^2$
Area of sheet $=$ Surface area of the tank
$L\times 2.5=752$

$L=300.8$ m
Length of the sheet $=300.8$ m
$\therefore$ cost of the sheet $=C=300.8\times 12.50$
$C=3760$