Răspuns :
Notam cu y pretul initial.
y+yx10%=220=>y+y=220:10%=>2y=220x100/10=>2y=22x100=>2y=2200=>y=2200:2 =>y=1100
y+yx10%=220=>y+y=220:10%=>2y=220x100/10=>2y=22x100=>2y=2200=>y=2200:2 =>y=1100
10 supra 100 se inmulteste cu 220=22 lei pt ca se taie zerouri cat arata zero!