Răspuns :
100 + 20 = 120
100 : 120 = 1,20
528 : 1,20 = 440 lei
100 + 10 = 110
100 : 110 = 1,10
528 : 1,10 = 400 lei
100 : 120 = 1,20
528 : 1,20 = 440 lei
100 + 10 = 110
100 : 110 = 1,10
528 : 1,10 = 400 lei
Dupa prima scumpire
x+10x/100=11x/10
Dupa a doua scumpire
11x/10+11x/10*20/100=528
11x/10+22x/100=528
132x=528*100
X=400pretul initial