Aptitude - Area - Discussion
Discussion Forum : Area - General Questions (Q.No. 15)
15.
A tank is 25 m long, 12 m wide and 6 m deep. The cost of plastering its walls and bottom at 75 paise per sq. m, is:
Answer: Option
Explanation:
| Area to be plastered | = [2(l + b) x h] + (l x b) |
| = {[2(25 + 12) x 6] + (25 x 12)} m2 | |
| = (444 + 300) m2 | |
| = 744 m2. |
 Cost of plastering = Rs. |
 |
744 x | 75 |  |
= Rs. 558. |
| 100 |
Discussion:
24 comments Page 1 of 3.
Mahesh said:
2 decades ago
Why (l x b) is there again?
Krishna said:
1 decade ago
i agree with mahesh plastering is done to the tank perimeter not area.... this is not filling water , which occupies area it is similar to fencing the rectangular field..
so i think area to be plastered is the perimeter
2(l+b)*h...
so i think area to be plastered is the perimeter
2(l+b)*h...
Sundar said:
1 decade ago
@All
The cost of plastering its 'walls' and 'bottom'.
Finding area:
For walls = [2(l + b) x h]
For bottom = (l x b)
So, total area to be plastered = [2(l + b) x h] + (l x b)
I think you got it.
The cost of plastering its 'walls' and 'bottom'.
Finding area:
For walls = [2(l + b) x h]
For bottom = (l x b)
So, total area to be plastered = [2(l + b) x h] + (l x b)
I think you got it.
Ashu said:
1 decade ago
For convinience the formula should be 2(lb+bh+hl)-area of the top which is lb
Syed said:
1 decade ago
instead of the fomula [2(l + b) x h] we can write 4(l*h)
Malar said:
1 decade ago
For walls its enough [2(l+b)] . Then why you multiply with h ?
Divya said:
1 decade ago
Formula for four walls is 2(l+b)*h so we have to multiply by h this is for four walls but here it is given as tank so v huv to cover the bottom area also so (l*b).
Hence to find we have to add both 2(l+b)h +(l*b).
Hence to find we have to add both 2(l+b)h +(l*b).
Vaishnavi said:
1 decade ago
@malar
2(l+b) is only the perimeter of the rectangle (2D) with only length and breadth and no thickness / depth.
Here it is the wall of the tank with depth of 6 m.
Hope you got the idea.
2(l+b) is only the perimeter of the rectangle (2D) with only length and breadth and no thickness / depth.
Here it is the wall of the tank with depth of 6 m.
Hope you got the idea.
Abc said:
1 decade ago
How you know the bottom is rectangular or may be any other?
Siva said:
1 decade ago
What is the formula if it is a room and need to plaster four walls, bottom and top as well ?
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