fie x pretul initial
10%x=10x/100=x/10 ->prima scumpire
x+x/10=(10x+x)/10=11x/10->pretul dupa prima scumpire
20%*11x/10=20*11x/1000-22x/100=11x/50-> a doua scumpire
11x/10+11x/50=(55x+11x)/50=66x/50=33x/25->pretul final
33x/25=660 |:33=>x/25=20=>x=25*20=500 lei
x=500 lei ->pretul initial
