A closed iron tank 12 m long, 9 m wide and 4 m deep is to be made.

Determine the cost of the iron sheet used at the rate of Rs. 5 per meter sheet, the sheet being 2 m wide.

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.

An Intiative by Sri Chaitanya

Rs 900

Rs 960

Rs 910

Rs 920

answer is B.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

Given the length, breadth, and depth of the closed iron tank is 12m, 9m, and 4m respectively.
A closed iron tank has
Length (l) = 12m
Breadth (b) = 9m
Depth (h) = 4m
Now, we will determine the total surface area (SA) of tank
Total surface area of tank

= 2 (l b + b h + l h)

, where l is the length, b is the breadth and h is the height of the cube.

⇒ S A = 2 [12 × 9 + 12 × 4 + 9 × 4] ⇒ S A = 2 [108 + 48 + 36] ⇒ S A = 2 × 192 ⇒ S A = 384 m 2

Then,
Length of the iron sheet used (L) =

Total surface area of tank Width of iron sheet

⇒ L = 3842 m

⇒ L = 192 m

To find the total cost of iron sheet
Total cost of iron sheet = Length of the iron sheet used

×

5

per

m

⟹Total cost = 192

×

Rs 5
⟹ Total cost = Rs 960
Hence, the total cost of the iron sheet used to make a closed iron tank 12m long, 9m wide and 4m deep is Rs 960.
Thus, option 2 is the correct option.

Watch 3-min video & get full concept clarity