Question

A hall is 40m long and 32m wide. The sum of areas of the floor and ceiling is equal to the area of four walls. Write the height of the hall (in m)

Answer 1

Step-by-step explanation:

length-40m

width-32m

height-length×width

-40m×32m

-1280m

is this correct

Answer 2

Step-by-step explanation:

Sum of areas of 4 walls = Sum of areas of floor and ceiling.  

Area of wall adjacent to the breadth of the room

=  Breadth ✕ Height

= 40 ✕ h , there are 2 such walls

Area of wall adjacent to the length of the room

= length of wall ✕ Height

= 32✕ h, there are 2 such walls

Area of roof = 40 ✕ 32

Area of floor = 40 × 32

⇒32 ✕ h + 32 ✕ h + 40 ✕ h + 40 ✕ h =  40 ✕ 32 + 40 ✕ 32

⇒2 ✕ 32 ✕ h + 2 ✕ 40 ✕ h = 2 ✕ 40 ✕ 32

⇒2 (32 ✕ h + 40 ✕ h) = 2 (40 ✕ 32)

⇒72h = 40 ✕ 32

⇒Therefore, height h = 17 m

Therefore volume = Length ✕ Breadth ✕ Height

= 40 ✕ 32 ✕ 17

= 21760 cubic metres.