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 7 of 8.
Anil said:
9 years ago
Imagine it as cuboid i.e it has different breadth and height also has length.
Given condition,
2(15h) = 2(15 * h) + 2(12 * h).
Solve this to get h.
lbh = v.
Given condition,
2(15h) = 2(15 * h) + 2(12 * h).
Solve this to get h.
lbh = v.
Patty said:
9 years ago
Surface area of cuboid is 2 (lb + bh + hl).
But surface area of 4 walls doesnt includes areas of floor+ceiling. Thats why Total area of walls = 2 (lb + bh + bl) - 2 (lb) = 2 (hb + lh) = 2(b + l)h.
But surface area of 4 walls doesnt includes areas of floor+ceiling. Thats why Total area of walls = 2 (lb + bh + bl) - 2 (lb) = 2 (hb + lh) = 2(b + l)h.
Vissu said:
9 years ago
Please anyone explain each and every step of the solution.
Annie said:
9 years ago
Main formula is : Area of 4 walls of a room = 2 (Length + Breadth) x Height. [step 4 to find height].
Area of four walls = (area of the base ) + (area of ceiling) [step 3].
Area of base is (l * b)[step 1].
Area of ceiling is (l * b)[step 2].
Volume = (l x b x h) cubic units [step 5].
Area of four walls = (area of the base ) + (area of ceiling) [step 3].
Area of base is (l * b)[step 1].
Area of ceiling is (l * b)[step 2].
Volume = (l x b x h) cubic units [step 5].
Saisowjanya.uriti said:
9 years ago
I think there is no need to take 2 (l+b). But why we consider that? Can anybody explain.
Prashant said:
9 years ago
Ceiling mean portion lies above floor i.e. roof so the area of floor equal to area of ceiling (l*h).
Gopal said:
1 decade ago
I can not understand the meaning of cube in answer.
Hardik said:
10 years ago
What is the volume of the hall formula?
Navdeep kaur said:
10 years ago
Hey, please solve the starting explanation clearly.
Swati said:
10 years ago
Please explain the question clearly. I don't understand.
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