Question

the length of a room is 3 and half time its width if the perimeter of the floor of the room is 90 M find the Length and width of the room

Answer 1

ATQ
$l = 3 \frac{1}{2} \times b$
2l=7b

l:b= 7:2
length = 7k : Breadth=2k
ATQ
2(7k+2k)=90
9k=45
k=5

so the length & breadth of the room are 35 ,10
$l = 35 \ \infty \: \: b = 10$