Question

A rectangular field has its breadth and length in the ratio 4 : 5. if the breadth of the field is 20 m less than the length, then the perimeter of the field in m is

Answer 1

Hy there,
Let length be x, breadth be y
Implies y/x=4/5
Implies 5y=4x
Also, y-20=x
X=20+y
Substituting it,
5y=4(20+y)
5y=80+4y
5y-4y=80
Implies y=80
Finding x,
5y=4x
5*80=4x
400=4x
X=400/4=100
Length is 100 metre, breadth is 80 metre.
Perimeter of rectangle=2(l+b)
=2(100+80)
=2(180)
=360 metre sq.
Hope it helps.
Thanks