Q10 of 99 Page 264

The area of four walls of a room is 42 sq. meter and area of floor is 12 sq. meter. Let us write by calculating the height of room if the length of room is 4 meter.

Let length of the room be L = 4m

Let breadth of the room be B = ?


We know, area of rectangle = length × breadth


Area of floor = L × B = 12m2 = 4 × B


So B = 3m


Let the height of room is H.


Area of four walls = 2(L × H) + 2(B × H) = 48m2


So (L × H) + (B × H) = 24m2


Substituting L and B,


3H + 4H = 24m2


7H = 24


Or H = 3.24m


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