Aptitude - Volume and Surface Area - Discussion
Discussion Forum : Volume and Surface Area - General Questions (Q.No. 3)
3.
A hall is 15 m long and 12 m broad. If the sum of the areas of the floor and the ceiling is equal to the sum of the areas of four walls, the volume of the hall is:
Answer: Option
Explanation:
2(15 + 12) x h = 2(15 x 12)
 h = |
180 | m = | 20 | m. |
| 27 | 3 |
 Volume = |
 |
15 x 12 x | 20 |  m3 |
= 1200 m3. |
| 3 |
Video Explanation: https://youtu.be/V8EQ1YIaH74
Discussion:
75 comments Page 3 of 8.
Jagruti said:
7 years ago
Thanks. @Sonu.
Ramesh said:
8 years ago
Thank for your explanation. @Sonu.
Geet said:
8 years ago
I cannot understand this! Please, anyone explain it.
Erika said:
8 years ago
Why isn't an area of four walls equal to 4*l*b?
Ankur said:
8 years ago
Thank you for explaining the answer in well and suitable form @Lokesh.
Ann said:
8 years ago
@Erika,
Here four walls does not include the floor and the ceiling which is the top floor. Out of the four walls, sum of the areas of 2 walls which are opposite to each other is length* height+ length*height= 2*length*height.
Similarly, the sum of the areas of the 2 remaining two walls which are opposite to each other is breadth*height+breadth*height=2* breadth*height. So, the sum of areas of 4 walls= 2lh+2bh=2h (l+b). While calculating the area of a wall must consider the height of the wall.
Here four walls does not include the floor and the ceiling which is the top floor. Out of the four walls, sum of the areas of 2 walls which are opposite to each other is length* height+ length*height= 2*length*height.
Similarly, the sum of the areas of the 2 remaining two walls which are opposite to each other is breadth*height+breadth*height=2* breadth*height. So, the sum of areas of 4 walls= 2lh+2bh=2h (l+b). While calculating the area of a wall must consider the height of the wall.
Harsh said:
9 years ago
I cannot understand this. Someone help me.
AARUSH said:
7 years ago
Thanks @Sonu.
Revanth said:
7 years ago
Thanks for the answer @Jay R.
Dashi said:
7 years ago
Please anyone explain me to understand this problem.
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