Question

the ratio between the length and breadth of a rectangle field is5:4. If the breadth is 20m less than the length,the perimeter of field is

Answer 1

let l=5x b=4x
perimeter= 2(l+b)
2(5x+4y)=0
5x+4y=0 eqn 1
according to problem
x+y-20=0
x+y=20
solving 1 and 2
5x+4y=0
x+y=20
gives
x=120
y=100
perimeter=2(220)
=440m