Question

Dacă 900 Kg de fier se extrage 150 Kg fier pur.Aflați cantitatea de minereu de fier din care se extrage 500 Kg fier pur

Answer 1

900kg.......150kg 
x kg..............500 kg

900/x=150/500
x=500x900/150
x=450000/150
x=3000kg

Answer 2

900 kg----------150 kg pur
x kg----------- 500 kg pur
x=500×900 l 150 = 45000 l 150 =3000 kg fier