Question

a closed iron tank 12 metre long 9 metre wide and 4 metre deep is to be made. determine the cost of iron sheet used at the rate of rupees 5 per metre sheets it is being 2 metre wide ​

Answer 1

AnswEr :

$\bold{Given} \begin{cases} \underline{ \footnotesize\sf{ \star \: \: Dimensions\:of\:the\:Tank :}} \\ \sf{Length \: (l)=12m} \\ \sf{Width \: (b)=9m} \\ \sf{Height \: (h)=4m}\\ \scriptsize\sf{Find \: Cost \: of \: Iron \: Sheet \: Used \: @5/m \:if \: Sheet\:is \: 2m \: wide}\end{cases}$

• we will find TSA of Cuboidal Tank :

⇒ TSA = 2 × (lb + bh + hl)

⇒ TSA = 2 × (12.9 + 9.4 + 4.12)

⇒ TSA = 2 × (108 + 36 + 48)

⇒ TSA = 2 × 192 m²

⇒ TSA = 384 m²

• length of Iron Sheet Required :

⇒ Length Required = $\sf\dfrac{Area}{Width\:of\:Iron\:Sheet}$

⇒ Length Required = $\sf\cancel\dfrac{384}{2}$

⇒ Length Required = 192 m

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• cost of Iron Sheet will be :

⇒ Total Cost = Length × Rate

⇒ Total Cost = 192 m × Rs. 5

⇒ Total Cost = Rs. 960

⠀

∴ Cost of Iron Sheet Required is Rs. 960

Answer 2

To Find :----

• cost of iron sheet used ?

Given :------

• length of tank = 12m
• Breadth of tank = 9m
• Depth of tank = 4m
• rate of iron sheet = 5/metre
• width of iron sheet = 2metre

Formula used :-----

• Total surface area of cuboid = 2(lb+bh+hl)
• length of iron sheet = Total area/width of iron sheet .

$\boxed{\fcolorbox{white}{pink}{ANSWER:-}}$

first we calculate total surface area of tank ,

TSA = 2(lb+bh+hl)

putting values we get:----

$TSA = 2(12 \times 9 + 9 \times 4 + 4 \times 12) \\ \\ TSA = 2(108 + 36 + 48) \\ \\ TSA = 2 \times 192 \\ \\ TSA = 384 \: m^{2}$

Now, length of iron sheet = Total Area/width of iron sheet

$length = \frac{384}{2} \\ \\ length = 192m$

Now, cost of 1metre iron sheet = Rs.5

so, cost of 192metre iron sheet = 192×5 = Rs.960 .

⛬ cost of iron sheet will be Rs.960 ..

(Hope it helps you)

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$\large\bold\star\underline\mathcal{Extra\:Brainly\:Knowledge:-}$

➠ Volume of cuboid = length × width × Height

➠ Diagonal of cuboid = √(l²+b²+h²)

➠ CSA of cuboid = 2(l+b)×h

$\mathcal{BE\:\:BRAINLY}$