Răspuns :
daca se scumpeste cu 20% si scade cu 10% rezulta ca se scumpeste cu 10%,asta inseamna 150x10 impartit la 100=iti da 15,apoi faci 150+15=165 pretu final
100%----------------------150
120%------------------------x
x =150 * 120 /100 = 180lei dupa scumpire
180lei------------------------100%
x-------------------------------90%
x = 180*90/100 = 162lei
120%------------------------x
x =150 * 120 /100 = 180lei dupa scumpire
180lei------------------------100%
x-------------------------------90%
x = 180*90/100 = 162lei