Respuesta :

540/x=100/18
(540/x)*x=(100/18)*x       - we multiply both sides of the equation by x
540=5.5555555555556*x       - we divide both sides of the equation by (5.5555555555556) to get x
540/5.5555555555556=x 
97.2=x 
x=97.2

now we have: 
18% of 540=97.2