Note: The height of the room must be 3 m instead of 3 cm because 3 cm is too small and it cannot be the height of a room.
Given:
Perimeter of the floor of a room = 18 metre
Height of the room = 3 metre
To find:
The area of 4 walls of the room.
Solution:
We know that, the area of 4 walls of the room is the curved surface area of the cuboid room.
The curved surface area of the cuboid is

Where, h is height, l is length and b is breadth.
Perimeter of the rectangular base is 2(l+b). So,

Putting the given values, we get


Therefore, the area of 4 walls of the room is 54 sq. metres.
-4x/7 > 10
Multiply both sides by 7:
-4x > 70
Divide both sides by -4"
x > 70 / -4
Simplify the fraction:
70/-4 = 35 / -2
Because the fraction is negative you need to reverse the inequality sign:
x < -35/2
The answer is the first one: {x|x < -35/2}
Twelve point nine plus eight equals twenty point nine (12.9 + 8 = 20.9)
Hope this helped :)