Question

a room is 15 m long and 10m broad if the area of its four walls is 350 m. square find the height of the room

Answer 1

Length of room = 15m 
Breadth of room= 10m
We know that area of 4 walls of cuboid = 2(Length + Breadth) × Height
                   350 m²                                = 2(15m + 10m) × Height 
                   350 m²                                = 50 m × Height
                   Height                                 = 350m²/50m = 7m
Therefore height of room is 7 meter 

Answer 2

Let the height be h m

area of the 4 walls = perimeter of the floor * height
               350 = 2 (l + b) h
                      = 2 (15+10) h
       h = 350/50 = 7 m