Respuesta :

1st find discount
18-13=5
5 is discount

discount from original
5/18=x%
percent means parts out of 100 so x%=x/100
5/18=x/100
multiply both sides by 900
250x=9
divide both sides by 250
x=27.77777
aprox 28%

answer is 28%
RELAXING NOICE
Relax