Question

Area of the four walls of a room is $108m^2$. If the height and length of the room are in the ratio of 2 : 5 and the height and breadth in the ratio 4 : 5, then the area, in $m^2$, of the floor of the room is

• A. 72
• B. 54
• C. 45
• D. 24

Answer 1

The correct option is C 45

Let $Length=l,breath=b,height=h$
Area of four walls = $2h(l+b)$ = $108m^2$
$h:l=2:5,h:b=4:5$ (Given)
$\therefore h:l:b=4:10:5$
Let $h=4x,l=10x,b=5x$
Now, the area of four walls, $2\times 4x\left(15x\right)=108$
$x^2=\frac{108}{120}$
Then the area of the floor is $l\times b=10x\times 5x=50x^2$
$=50\times \frac{108}{120}=45m^2$
Hence, option 'C' is correct.