Aptitude - Volume and Surface Area - Discussion
Discussion Forum : Volume and Surface Area - General Questions (Q.No. 9)
9.
A cistern 6m long and 4 m wide contains water up to a depth of 1 m 25 cm. The total area of the wet surface is:
Answer: Option
Explanation:
| Area of the wet surface | = [2(lb + bh + lh) - lb] |
| = 2(bh + lh) + lb | |
| = [2 (4 x 1.25 + 6 x 1.25) + 6 x 4] m2 | |
| = 49 m2. |
Discussion:
40 comments Page 1 of 4.
Mohammad Asif said:
3 years ago
@All.
It should be clearly given that tha water filling height is measured from top or bottom of the container.
Am I right?
It should be clearly given that tha water filling height is measured from top or bottom of the container.
Am I right?
(8)
Kanna29 said:
3 years ago
@All.
Here, The uppermost surface also has some specific height. Then why everyone not considering it , just multiple l*b and not h?
Here, The uppermost surface also has some specific height. Then why everyone not considering it , just multiple l*b and not h?
(2)
Kishan said:
5 years ago
@All.
2(lb+ lh+ bh) gives the total surface area, which includes 4 walls, ceiling and floor. If we are asked the area of a wet surface, only the walls will be wet, and the floor. Ceiling won't be wet, so we need to subtract ceiling's area from the total surface area i.e. L*B
Therefore 2(lb + bh + lh) - lb.
2(lb+ lh+ bh) gives the total surface area, which includes 4 walls, ceiling and floor. If we are asked the area of a wet surface, only the walls will be wet, and the floor. Ceiling won't be wet, so we need to subtract ceiling's area from the total surface area i.e. L*B
Therefore 2(lb + bh + lh) - lb.
(40)
Shenga said:
6 years ago
See @nitya's answer.
(2)
Vicky said:
7 years ago
Good explanation, thanks all.
(1)
Sanjana said:
8 years ago
Please explain the formula 2lh+2bh+lb.
(1)
Ankit rai said:
8 years ago
But only the wet area is taken as cuboid so why do we subtract lb?
(1)
Raju said:
8 years ago
Good explanation, Thanks @Mubarak.
Mubarak said:
8 years ago
We have 5 wet sides i.e., complete bottom portion (6mx4m = 24m2) and four walls.
Area of 4 walls = perimeter*height.
= 2(6+4)*1.25.
= 20*1.25 =25.
So total wet area = 24+25 = 49 cub.mtr.
Area of 4 walls = perimeter*height.
= 2(6+4)*1.25.
= 20*1.25 =25.
So total wet area = 24+25 = 49 cub.mtr.
(5)
Sunny Rao said:
8 years ago
Why it's not be taken as three parts of the cuboid.
1st part is the big one 2nd part is a wet one and the third part is apart from both which is 2nd biggest cuboid.
And if we will subtract from 3rd one's surface area from 1st, then automatically we will get 2nd one which is the wet part.
Isn't it?
1st part is the big one 2nd part is a wet one and the third part is apart from both which is 2nd biggest cuboid.
And if we will subtract from 3rd one's surface area from 1st, then automatically we will get 2nd one which is the wet part.
Isn't it?
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