Wallpaper,312 cm long and 25 cm wideis required to cover the walls of a room.Length of the room is 7 m and its breadth is twice its height .Determine the height of the room...

pls help

Question

Wallpaper,312 cm long and 25 cm wideis required to cover the
walls of a room Length of the room is 7 m and its breadth is twice
its height Determine the height of the room
pls help

Vimala · Accepted Answer

The length of the room is $l = 7 m$

Let h be the height of the room

Then width of the room is w = 2h.

The wall paper can be pasted on the four walls and hence we need to find the area of the four walls.

Thus,

$A r e a o f f o u r w a l l s = 2 (l + w) h$

The area of the given wall paper is $\frac{312 \times 25}{100 \times 100}$ .

Therefore,

$A r e a o f f o u r w a l l s = 2 (7 + 2 h) h \frac{312 \times 25}{100 \times 100} = 2 (7 + 2 h) h \frac{156 \times 25}{100 \times 100} = 7 h + 2 h^{2} 2 h^{2} + 7 h - 0.39 = 0$

Use quadratic formula to solve the above equation.

Thus, neglecting the negative value, h = 0.05m

That is height of the room is h = 5 cm which is impossible.

Please check your question...........

Wallpaper,312 cm long and 25 cm wideis required to cover the walls of a room.Length of the room is 7 m and its breadth is twice its height .Determine the height of the room... pls help

Wallpaper,312 cm long and 25 cm wideis required to cover the walls of a room.Length of the room is 7 m and its breadth is twice its height .Determine the height of the room...

pls help